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Title: Easy Biology For Class 9-10
Description: Reading this book you can easily learn biology.
Description: Reading this book you can easily learn biology.
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Prescribed by National Curriculum and Textbook Board
as a Textbook for class Nine-Ten from the academic year 2013
Biology
Class : Nine - Ten
Written by
S
...
Haider
Dr
...
Niamul Naser
Gul Anar Ahmed
Md
...
Syed Mohammad Humayun Kabir
Dr
...
Imdadul Hoque
Translated by
Rajat Kanti Shome
Gul Anar Ahmed
Qji Neamul Haque
National Curriculum and Textbook Board, Dhaka
Published by
National Curriculum and Textbook Board
69-70, Motijheel Commercial Area, Dhaka
[All rights reserved by the Publisher]
Trial Edition
First Publication : December 2012
Co-ordinated by
Fatema Nasima Akhter
Computer Compose
Laser Scan Ltd
...
To cope with the
challenges of the fast changing world and to lead Bangladesh to the doorstep of development and
prosperity, a well educated and skilled population is needed
...
Besides, the other aims also include
expansion and consolidation of the basic knowledge and skills of the learners acquired at the
primary level in order to make them fit for entry into higher education
...
Keeping the aims and objectives of National Education Policy 2010 ahead, the curriculum at the
secondary level has been revised
...
Along with these expected learning outcomes have been
determined based on the learners’ age, merit and level of acquisition
...
Efforts
have also been made to apply science in all spheres of our life in order to build a nation advanced
in science
...
In the light of the present curriculum almost all the textbooks at the secondary level have been
introduced
...
While selecting the contexts and their
presentation special attention has been given on the expansion of the learner’s creative faculty
...
By adding variety of activities, creative and other questions
evaluation has also been made creative
...
The main purpose of learning
Biology is to acquire theoritical and practical education from life
...
This scope for knowing the living world with enjoyment has
been created in the new Biology curriculum of classes Nine-Ten
...
This
will reduce learners’ tendency for rote-learning to a great extent and they will be able to internalise
and apply the achieved knowledge in addition to analysing and evaluating things
...
Therefor e we welcome with our highest
consideration any suggestions, both constructive and rationale as well for the further improvement
of the book
...
We will continue our effort to make the next edition of this
book more beautiful, decent and free from any types of errors
...
We hope this book will ensure joyful reading and achievement of expected
skills from the learners
...
Md
...
CONTENTS
Chapter
Page No
One
Lesson on Life
1
Two
Cell and Tissue of Organism
11
Three
Cell Division
32
Four
Bioenergetics
40
Five
Food, Nutrition and Digestion
54
Six
Transport in Organisms
82
Seven
Exchange of Gases
104
Eight
Human Excretion
117
Nine
Firmness and Locomotion
124
Ten
Co-ordination Process in Animal
134
Eleven
Reproduction
152
Twelve
Heredity in Organisms and Evolution
167
Thirteen
Environment around Life
178
Fourteen
Biotechnology
193
Biology
1
Chapter One
Lesson on Life
Biology, an immensely important area of science, plays a variety of crucial roles in
ensuring protection and welfare of all living beings on earth
...
In that case, biology can help human to face some
critical challenges of the century, and some of these are the production of food,
development of medical science and conservation of organisms in their hostile
environment
...
At the end of the chapter, we will be able to
x Explain the general concept of biology
...
x Explain the classification of organisms
...
x Describe the systems of classification of organisms
...
x Become conscious of the necessity of classification of organisms in practical life
...
The characteristics of nonliving things are usually discussed in Physics and Chemistry
...
It is one of the oldest branches of natural science
...
By studying biology, one can acquire interesting knowledge of different plants and
animals and human life
...
This is why a good command of biology plays an important role in
knowing more about the different parts and organ structure of organisms, different
chemical activities in them, their adaptation with their environment, their intake of
nutrition and reproduction
...
Science has a great contribution in our everyday activities and developing our
experience
...
At the time of walking, our muscles conduct our legs,
our nerves move our muscles and the blood circulation in our muscles provides them
with oxygen, nutrition and strength
...
For the maintenance of biological existence, all
living organisms require oxygen and energy
...
Biology is one of the fundamental branches of science
...
" Greek
philosopher Aristotle (384BC – 322BC) is called the father of biology
...
Branches of Biology
Based on the type of organism, biology is divided into two branches – Botany and
Zoology
...
Physical Biology
In the field of physical biology, theoretical concepts are usually discussed
...
1
...
It is usually
divided into two branches – external and internal morphology
...
2
...
Biology
3
3
...
Besides, detailed description of all the physiological process of
organisms is found in it
...
Histology: The microscopic structure, arrangement and function of plant and animal
tissues are studied in this subject
...
Embryology: The branch of biology discusses the development of embryo of
organisms
...
Cytology: The structure, function and division of an individual cell in a body of
organisms are studied in this field of biology
...
Genetics: The branch of biology deals with genes and heredity
...
Evolution: The gradual development of life and organisms over successive
generations on earth is studied in this subject
...
Ecology: It is the science of reciprocal relationship between organisms and their
environment
...
Endocrinology: The field of science deals with the study of endocrine glands and
hormones secreted by them in a body of organisms
...
Biogeography: The branch of biology studies the geographical distribution of
organisms, past and present, throughout the landscape of planet earth including the
knowledge of classifying bio-geographical patterns
...
Palaeontology: Science of the prehistoric life forms and fossils;
2
...
Parasitology: Science related to parasitism, life process of parasitic organisms and
diseases caused by them;
4
...
Entomology: Science related to the study of life, merit, demerit, and control of
insects including the losses caused by them;
6
...
Agriculture: Science concerning agriculture;
8
...
;
9
...
Biochemistry: Science connected to biochemical process and diseases of organisms;
11
...
Environmental Science: Science related to environment;
4
Biology
13
...
Forestry: Science related to forest, management and conservation of its resources;
15
...
Pharmacy: Science dealing with technology and industry of medicine;
17
...
Bioinformatics: Biological information based on computer technology, information
on the analysis of cancer, for example
...
Classification:
About four million of different plant species and thirteen million of animal species have
been named and described till today
...
It is assumed that
the number will reach a crore in future when the description of all the organisms will be
ended
...
Many years back natural scientists felt
the necessity to classify living world following a natural system
...
The aim of classification
is only one to know the vast and diverse living world accurately and classify them with
little effort in a short period of time
...
In 1735 at the age of 28, he
took his doctoral degree in medicine at the University of Harderwijk, and in 1741 he was
appointed Professor of Medicine at Uppsala University
...
He thoroughly reconstructed and expanded the Botanical Garden
...
He classified living world
into two kingdoms – Plant and Animal
...
He first defined the term genus and species in his
book
...
On the basis of each other’s similarity and dissimilarity, grouping organisms
is called classification
...
To document the accumulated information systematically focusing on the
diversity of living organisms, introduce the total knowledge concisely and take proper
steps after identifying organisms to conserve them or increase the number of species for
the well-being of human beings and the living world are the objectives of classification
...
With the progress of science, on the basis of data collected from time to time, for
instance, the type of DNA or RNA in a cell, features and number of cell in a living body
and mode of nutrition that a cell adopts, a five-kingdom classification was proposed by
R
...
Whittaker in 1969
...
She divided the whole living world into two superkingdoms and grouped the five kingdoms under these two super-kingdoms
...
Kingdom-1: Monera
Characteristics:
They
are
mostly
unicellular,
filamentous,
colonial
or
a
b
mycelial
...
1 a) Bacteria b) Nostoc (Blue green algae)
membrane and nucleolus in their cells
...
Cell divides through the process of binary fission
...
Example: Bacteria, Blue green algae;
Superkingdom-2: Eukaryota
They are eukaryotic and unicellular or multicellular
and live induvidually or in a colonial form
...
Their cells contain nuclear materials
Figure: 1
...
In chromatin
material, there are DNA, RNA and protein
...
Their modes of nutrition are absorption,
ingestion or photosynthesis
...
No embryo is developed in them
...
Their body is constituted
with a single cell or mycelium
...
3 a) Penicillium b) Mashroom
organised
...
Their
mode of nutrition is absorption
...
They reproduce by haploid spores
...
Example: Yeast, Penicillium, Mushroom etc
...
Advanced tissue
systems are found in them
...
They are mostly terrestrial but there are
also many aquatic species under
this kingdom
...
They are
archegoniates and flowering plants
...
4 a) Spirogyra Multicellular algae
b) Jackfruit tree
Biology
7
Example: Advanced green plants, multicellular algae;
Kingdom-5: Animalia
Characteristics: They are eukaryotic and multicellular animals
...
Because of having no plastid in their cells, they are
heterotrophs, and so they depend on other organisms
for their food
...
They have advanced and complex type of tissue
systems
...
Haploid gametes are usually produced
in the reproductive organs of mature and diploid male
and female
...
Figure: 1
...
Thomas Cavlier-Smith from Oxford University divided the kingdom Protista of living
world into two groups, and renamed the kingdom Monera as the Kingdom of Bacteria in
2004
...
You will learn more
about it at your higher level of education
...
The largest
classification rank is kingdom, and the smallest classification rank is species
...
System of Binomial Nomenclature
The scientific name of an organism is constituted with two parts
...
The scientific name of potato is Solanum tuberosome, for example
...
The
system of scientific naming of an organism with two parts is termed as binomial nomenclature
...
The scientific naming of an organism is accomplished in accordance with
some rules and regulations set internationally
...
In fact, the codes are documented in a printed form
...
The great Swedish naturalist Carolus Linnaeus laid the foundations for the modern
simpler system of naming organisms and effectively began the task with his book
Species Plantarum in 1753; the original description of naming organism is found in the
tenth edition of his work Systema naturae in 1757
...
The introduction of the formal system of naming organism by Carolus Linnaeus is
undoubtedly a striking step in the history of biology
...
The language of scientific naming of an organism would be Latin
...
Every scientific name should have two parts, and the genus name always comes first
followed by the species name
...
The scientific name of any organism should have to be unique because a same
legitimate name cannot be used for naming two distinct organisms
...
The first alphabet of the first name would be in capital letter with the remaining
alphabets in small type, and the second part of the name totally would be with small
letters
...
5
...
RiceOryza sativa, Katla fish- Catla catla, for example
...
When a scientific name would be written in hand, two parts of it should be
separately underlined
...
7
...
8
...
Binomial names of some organisms:
General name
Scientific name
Rice
Oryza sativa
Jute
Corchorus capsularis
Mango
Mangifera indica
Jackfruit
Artocarpus heterophyllus
Water lily
Nymphaea nouchali
Jaba
Hibiscus rosa-sinensis
Causal organisms of cholera
Vibrio cholerae
Causal organisms of malaria
Plasmodium vivax
Cockroach
Periplaneta americana
Honey bee
Apis cerana
Ilish
Tenualosa ilisha
Biology
Asian toad
Oriental Magpie-Robin
Tiger
Human
9
Bufo melanostictus
Copsychus saularis
Panthera tigris
Homo sapiens
Exercise
Short answer questions:
1
...
Write down the name of physical branches of biology?
3
...
What is binomial nomenclature?
5
...
Essay type questions:
1
...
In which branch of biology are insects discussed?
a
...
Ecology
c
...
Microbiology
2
...
to know about the sub-ranks of organism
Cellmembrane
Cellwall
ii
...
to present the knowledge in detail
Cytoplasm
Mesosome
Which one of the following is correct?
a
...
i & ii
Flagellum
c
...
i, ii & iii
look at the stem and answer the question 3 & 4
...
What is the name of the organism shown in the picture above?
a
...
Diatom
c
...
acterium
4
...
i
...
unable to produce food
iii
...
i & ii
b
...
i & iii
d
...
a
...
c
...
What are the units of classification?
Why is genetics called the physical branch of biology?
How will you maintain the continuity in naming the plant in figure 2?
Analyse with explanation which organism is more advanced between the two shown
in figure 1 and figure 2
...
Now, based on the previous idea, you will be able to learn more about it
...
At the end of this chapter, we will be able to
x Explain the functions of main organelles of plant and animal cells
...
x Explain the role of different types of cell in performing properly the function of
nerve, muscle, blood, skin and bone
...
x Explain plant tissues
...
x Evaluate the functions of tissue on the basis of grouping the similar type of cells and
performing the same action
...
x Explain the concept and importance of organ and organ system
...
x Use a microscope properly
...
You studied at your previous level of education that the cell is the structural unit of an
organism
...
What is a living cell? Some scientists describe a living cell as the unit of
structure and biological function of an organism
...
Types of Cell
On the basis of the organisation of nucleus, cells can be divided into two types –
prokaryotic cell and eukaryotic cell
...
This is why it is called a cell with a
primitive type of nucleus
...
Nuclear materials in
a prokaryotic cell are not surrounded by any nuclear membrane
...
Though the cell organelles such as mitochondria, plastids, endoplasmic
reticule etc
...
Only the
unwrapped DNA constitutes the chromosomal structure of a prokaryotic cell
...
b) Eukaryotic cell:
In this type of cell, nucleus is well structured that means nuclear materials are well
organised and surrounded by a nuclear membrane
...
From algae to higher flowering plants and
from Amoeba to advanced animals, the basic structural and functional component is
eukaryotic type of cell
...
On the basis of function, there are two other types of cells: somatic cell and gametic cell
...
The cell divides through the process of binary fission and mitotic division
...
Moreover, cells take part in the organisation of different
organs and organ systems
...
Primordial germ cells divide through
meiotic division and produce gametic cells
...
A new living body is commenced after the
fusion of male and female gametes
...
Zygote is the first cell produced after the union of male and female gametic cells
...
Biology
13
Functions of the Main Organelles of Plant and Animal Cells
We will be familiar with some cell organelles, visible under an electron microscope
...
It is
composed of inert materials
...
Cellulose, hemicelluloses, lignin, pectin, suberin are the chemical components of a plant
cell wall
...
The primary cell wall is
single layered
...
At the time of
development of secondary cell wall, some
cavities are formed and they are called pits
...
It gives a cell its rigidity
...
For
exchanging materials with the adjacent cell, plasmodesmata are formed in a cell wall
...
There is no cell wall around an
animal cell
...
In a plant cell, cell
membrane is attached with the cell wall from the
inner side of the cell
...
The foldings of a cell membrane
are called microvilli
...
For its being selectively
permeable, the membrane can control the
movement of water and minerals through the process of osmosis, and separates a cell
form its neighbouring cells
...
The semi-transparent, jel-like, semisolid substance in a cell is called
protoplasm
...
Outside
the nucleus, the harbouring jel-like substance is called cytoplasm
...
They have different functions
...
1
...
This important organelle plays a very important role in
cellular respiration
...
The inner membrane has inflodings called cristae
...
The space
enclosed by the inner membrane is matrix containing a highly concentrated mixture of
hundreds enzymes, ribosomes, RNA and
mitochondrial DNA
...
The
process has mainly three stages: glycolysis, the
Kreb’s cycle and electron transport system
...
A series of biochemical
reactions of Kreb’s cycle occur in mitochondria
of a cell
...
In the process,
energy is, ultimately, produced
...
An organism uses the energy to perform different functions
...
2
...
The main functions of
a plastid are to produce and store food, and cause the charming and colourful appearance
of flowers, fruits and leaves of a plant
...
There are three categories of plastids: chloroplast, chromoplast
and leucoplast
...
They are found in the
cells of leaves, young stems and other green parts of a plant
...
This captured solar energy
helps produce simple carbohydrates from water and carbon dioxide taken from air with
the help of many enzymes in stroma
...
Besides, the pigments carotenoids are also present in them
...
The
photosynthetic pigment xanthophylls, carotene, phycoerythrin, phycocyanin etc
...
The
flowers, leaves and other parts of a plant assume their attractive colourful appearance
from the mixture of those pigments
...
Their main purpose is to make flower attractive for pollination
...
c) Leucoplast: Leucoplasts are non-pigmented in contrast to other plastids
...
Their main function is the storage of food
...
Activity: Drawing a diagram of a chloroplast;
Essentials: Poster paper, sign pen & a picture of a chloroplast;
After drawing a diagram of chloroplast, present it before the students in the classroom
hanging from a board
...
Centriole:
centriole is a hollow cylindrical
structure composed of nine triplets of microtubules,
fibers of protein, and found in an animal cell
...
It is composed of two un-overlapped centrioles
surrounded by cytoplasm condensed with a mass of
protein
...
At the time of the division of a
nucleus in an animal cell, their main function is to
organise astral rays
...
Ribosome: Ribosomes are found in all living cells
...
The bondage in polypeptide
chains of protein is carried out by ribosome
...
5
...
It
is composed of stacks of membrane-bound structure
known as cisternae and vesicles
...
It
involves in the secretion of some hormones and some
other different substances in a living cell
...
Sometime, golgi body stores protein
...
Endoplasmic reticulum: Ribosomes are
studded with the cytoplasmic side of rough endoplasmic reticulum, and so proteins are
synthesized in these sites
...
Sometimes endoplasmic
reticulum is stretched up to cytoplasmic membrane, and thus it is guessed that enzymes
towards other cells and other substances produced inside the cell are transported by the
endoplasmic reticulum
...
in a cell
...
7
...
The centrioles in a centrosome develop astral rays, thus they
play a significant role in constructing spindle apparatus
...
8
...
Its main function is to
contain cell sap
...
are found in a cell vacuole
...
If present in any animal cell, it usually is
much smaller
...
Lysosome: Lysosomes break down waste materials in a
cell
...
Moreover, it protects cells by engulfing unexpectedly
invaded microorganisms, viruses and bacteria
...
They are found
in animal cells
...
Nucleus: The nucleus is a membrane bound prominent
organelle found in the eukaryotic cells
...
Mature sieve cells and red blood
cells lack nucleus
...
A
well structured nucleus has the following parts:
a) Nuclear membrane: The membrane that encloses the
nucleus is called nuclear membrane
...
In this membrane, there are some channels called nucleopores
...
The membrane separates the
contents of a nucleus from cytoplasm
...
It is similar
to the cytoplasm of a cell
...
Biology
17
c) Nucleolus: In a nucleus round shaped structure attached with a chormosome is
called nucleolus
...
Its main function is to assemble ribosomes in an eukaryotic cell
...
Chromatin fibers get super coiled during
nuclear division and become more condensed, and then they are called chromosomes
...
They are the units of heredity, and pass
genetic information from generation to generation
...
Chromosomes contain
genes, and thus carry hereditary trait from generation to generation
...
Functions of
unicellular or multicellular animals are performed in different ways
...
In multicellular animals there are differences and variations in cells
...
These cells are
to receive stimuli and send it to the brain and again, sends off motor impulses from the
brain to the definite organ
...
Due to the lack of different kinds of nerve cells most of the animals can not differentiate
the exact colour of the objects just like human being
...
Muscle cells are used in writing, walking and movement
...
Red blood corpuscles absorbs oxygen from lung and
transports oxygen by the heart to different cell’s of the body through arteries and
capillaries
...
Platelets are responsible for starting the process of blood clotting
...
Besides making body covering integumentary cells performs
different functions according to its location
...
Sweat secretes from the sweat gland in particular space
...
Bone cells are very much important to build structure, shape, growth of the bones etc
...
Plant tissue can be grouped into two types: simple tissue
and complex tissue
...
On the basis of the nature of cell, simple tissues are divided into
three types: 1) Parenchyma, 2) Collenchyma and 3) Sclerenchyma
...
The cells of this type are living, isodiametric, thin walled and turgid with
protoplasm
...
The cells are thin
walled, and the walls are composed of cellulose
...
The parenchyma cells with air filled
spaces are called aerenchyma, that usually found in aquatic plants
...
2) Collenchyma: Collenchyma tissues are the special type of cells
...
Their walls are
irregularly thickened with some corners
...
Intercellular spaces may be present in them
...
Their main functions are to produce food
and provide the plant or plant parts with the mechanical support, rigidity
...
This kind of tissue provides rigidity to the
young and supple stems, for example, the stems of Gourd (Cucurbita sp) and Leucas
(Leucas lavandifolia)
...
11: Different types of simple tissue, a- Parenchyma, b-Collenchyma, C-Sclerenchyma
3) Sclerenchyma: The cells of this tissue are hard, much elongated with thick walls
...
Though, in early stage of their
development, the sclerenchyma cells are alive, soon they become dead losing the
living protoplasm when they get mature
...
There are two types of sclerenchyma cells, namely fibers and sclerides
...
In their walls they have pores called
pits
...
b) Sclerides: Because of their hardness, they are called stone cells
...
Their secondary cell walls are very durable, thick and lignified
...
The walls of the cells are pitted
...
In the petioles
of leaves, they may be present in cluster form associated with epidermis, xylem and
phloem
...
Draw the labeled diagrams of three types of tissue, and present the differences
between them
...
They conduct water, minerals and
prepared food, and this is why they are also called
conducting tissue
...
Xylem and phloem form together the
conducting structure of vascular bundle
...
Xylem developed during primary growth
from procambium is called primary xylem
...
Primary xylem comprises protoxylem
and metaxylem
...
Protoxylem is distinguished by narrower vessel developed from smaller cells but metaxylem
cells are usually larger
...
a) Tracheids: Tracheids are elongated cells with slender and sharp ends
...
Thickening of walls is of different types, such
as, elliptical, spiral, scalariform, reticulate and pitted
...
Its main function is to provide sap
conduction-related organ with proper rigidity
...
b) Vessels: Vessels are short, tube in structure connected
end to end
...
This is why for the ascending of sap, a narrow
continuous channel is developed
...
Vessels walls also become
differently thickened like tracheids, such as scalariform, spiral, elliptical, pitted etc
...
But they may be much longer in trees and
creepers
...
In some advanced
members of gymnosperms such as Gnetum contains primary type of vessels
...
c) Xylem parenchyma: The parenchyma cells in xylem are called xylem parenchyma
or wood parenchyma
...
The parenchyma cells in
primary xylem have thin walls, but those of in secondary xylem are thick walled
...
d) Xylem fiber: The sclerenchyma cells in xylem are called xylem fibers or wood
fibers
...
Mature cells do not contain
protoplasm, and so, become dead
...
They are present in the xylem throughout dicots
...
Phloem: The phloem tissue organises vascular bundle in association with xylem
...
This type of tissue is composed of
sieve tube, companion cell, phloem
parenchyma and phloem fiber
...
Sieve cells arranged end to end and make
a tubular structure called sieve tube
...
The
protoplasm in a sieve cell remains little
aside and closer to the wall, so that a
hollow lumen is developed for the
conduction of food
...
Mature sieve cells do not contain
nucleus
...
Their main function is to conduct food
produced in leaves to the different parts of a plant
...
Its nucleus
is much larger
...
A companion cell is turgid with protoplasm
and thin-walled
...
c) Phloem parenchyma: The parenchyma cells in phloem is called phloem
parenchyma
...
They help store and conduct food
...
d) Phloem fiber: Phloem fibers are sclerenchyma cells
...
They are also called bast fibers
...
These types of fibers are developed at the time of secondary growth of plant
parts
...
Through the phloem tissue, food
produced in leaves and stored in roots are simultaneously conducted up and down
...
Arising from the embryonic cell layer, certain one or more than one type of
cells when remaining in a particular place of the animals body collectively perform a
common function, are collectively called the Tissue
...
The subject in which the
different types of tissue are discussed is called Histology
...
For example : red blood corpuscles, white blood
corpuscles, platelets are different types of cells
...
The
liquid connective tissue take part in different physiological processes
...
The functions of these tissues are described below
...
Epithelial Tissue :
The cells of the epithelial tissue lie closely or side by side on a basement membrane
...
Example : Wall of the Bowman’s capsule of Kidney
...
b) Cuboidal epithelial tissue : Cells of this tissue are cuboidal; i
...
the length, and
height of the cells are nearly equal
...
Mainly active in transportation and
covering
...
Example : In the internal wall of intestine of vertebrate animals
...
Matrix is absent in epithelial tissue
...
Simple epithelial tissue : On basement membrane the cells are arranged in a single
layer
...
ii
...
Example : Integument of vertebrate animals
...
Pseudo stratified epithelial tissue : Cells of this tissue are arranged in a single layer
on basement membrane
...
So this tissue appears
to be stratified tissue
...
Besides, the cells of epithelial tissue are transformed variously for different functions As:
Biology
23
1
...
2
...
3
...
4
...
Taking part in reproduction, they maintain the continuation of
species
...
Being transformed, this tissue takes part in protection, secretion, absorption, diffusion,
transportation etc
...
2
...
On the basis of structure and function connective
tissue is mainly of three types
...
Fibrous connective tissue: This type of connective tissue lies below the bodyintegument and sparsely in muscles
...
b
...
Skeletal tissue forms the skeletal system of
the body
...
Produces various types of blood corpuscles
...
Depending on the formation, skeletal tissue is of two types
...
Its matrix is hard but soft and the
cells contain lacunae
...
Other than that humerus, femur etc
...
Bone is hard, fragile and inflexible skeletal connective
tissue
...
c
...
Different kinds of organic colloids are soluble in the matrix
...
Blood is a type of alkaline, slightly saline, red colored liquid connective tissue
...
In worm
24
Biology
blooded animal it maintains body temperature balance
...
Plasma is the liquid
part of blood
...
The organic substances include various types of blood protein and
waste materials
...
As : Red blood corpuscle or Erythrocyte,
White blood corpuscle or Leucocyte, Thrombocyte or platelets
...
The red colur of blood is due to the
presence of haemoglobin
...
Leucocytes destroy the microorganisms and protects the body against diseases
...
Thrombocytes take part in blood
coagulation or blood clotting
...
That is called lymphatic system
...
Lymph contains lymphocyte cell
...
Red blood corpuscles : It contains an iron compound named haemoglobin
...
Haemoglobin easily mixes with
oxygen to form ox haemoglobin compound
...
When necessary oxygen can mix with haemoglobin and
forms oxi haemoglobin
...
White blood corpuscle or Leucocyte : Generally lack definite shape and are nucleated
...
Leucocytes destroy
the microorganisms and protects the body against diseases
...
These are
usually nucleated and spindle shaped
...
Many thrombocytes take part in blood coagulation or blood clotting
...
That is called lymphatic system
...
Lymph
contains lymphocyte cell
...
Biology
25
3
...
Matrix is nearly absent in muscular tissue
...
Myofibril provided with transverse stirations are called striated muscles and striation less
myofibril is smooth muscle
...
On the basis of location, structure
and functions, muscle tissue is of three types
...
b,
Involuntary mascular tissue cardiac muscle
...
Voluntary or striated muscular tissue : It can be contracted or expanded at the will
of the animal
...
These have generally more than one nucleus
...
This muscle is also called marked or skeletal
muscle
...
b
...
This muscle tissue is spindle shaped and faintly branched
...
That is why this muscle is called unmarked smooth
muscle
...
of the vertebrate animals
...
Such as : intestinal peristalsis in food digestion
...
Cardiac muscle : The special type of involuntary muscle that form the heart of
vertebrate animals in called the cardiac muscle
...
Between the cells of this tissue intercalated disc are present
...
That
is, the structure of heart muscle is like that of voluntary muscle and the function is like
that of involuntary muscle
...
Through rhythmic contraction and
relaxation, the cardiac muscle control the circulation of blood within the body from a
particular stage of the embryonic condition till the last moment of death
...
Nerve tissue : The particular type of tissue which forms the nervous system is called
nervous tissue
...
the nervous tissue can transmit it within the body and according to that can make the
appropriate response
...
A typical neuron
has three parts as : 1) cell body, 2) dendrite and 3) axon
...
Cytoplasm of the cell
contains mitochondria, ribosome, golgibody, endoplasmic
reticulum etc
...
From the cell body of
the neuron a long nerve fibre which is attached with the
dendrite of neuron is called axon
...
Between the adjoining neurons a bridge is formed by the union
of axon of a neuron with the dendrite of the other
...
Through the synapse nerve stimulus from a neuron is
transmitted to the next neurons
...
In higher
animals nerve tissues store memory and controls works of different organs of the body
and coordinate among them
...
That is to say in any organ
there may be one or more than one type of tissues and that organ can perform a
particular work
...
Necessary organs of human body : According to location there are two types of organs in
human body
...
are discussed is called External Morphology
...
Stomach, duodenum, ileum, rectum, heart, liver, pancreas, spleen, lung, kidney,
testis, ovary etc
...
For performing various physiological functions
...
in man and in other animal several organs together form the
organ system
...
2
...
Digestive system : This system is associated with ingestion of food, digestion,
absorption and removal of undigested faecal materials
...
As:
Digestive canal : This canal is formed with mouth aperture, mouth cavity, pharynx,
oesophagus, stomach, duodenum, ileum, rectum and anus
...
2
...
This system
with the help of oxygen taken from the environment produces energy by the oxidation of
food present in the body cell
...
3
...
Nervous system is formed of
brain, spinal cord and cranial nerves and spinal nerves
...
This part of the nervous system controls
the involuntary works of the body
...
The Excretory system : Due to various physiological metabolic reactions some waste
materials are produced within the body as by-products
...
So these to be removed
...
The system by which the
excretion is performed is called the excretory system
...
28
Biology
5
...
This system consists of
gamete producing and embryo bearing organs
...
Man is unisexual
...
6
...
This system covers the body, protects form external injury and attack
of microbes
...
7
...
These produce the hormones
...
Blood carries the hormone from one place to another
...
Microscope
So, an arm is important to a fighter and a telescope to an astronomer, the instrument
microscope is essentially helpful to every student of biology
...
The compound microscope you
have in your school is equipped with the system of observing very small objects with the
help of light
...
Light microscopes
are of two types, such as- simple and compound light
microscope
...
Two clips are attached on two
upper sides of the stage to hold the slide with object to be
observed
...
A
continuos tube from the base holds a lens in its arm with a ring
...
If needed, the task of observing an
object can be started by focusing on it with the reflected
light
...
Different parts of compound microscope
It is better to understand different parts of a compound
microscope before using the instrument
...
The base
on which the whole microscope is rested is called foot
...
There is a
Biology
29
sub-staged two-sided light reflecting mirror
...
The stage is attached with the upper part
of the metallic body
...
In some cases, condensers can be attached just below the hole
...
This tube and the curved part are called body tube and handle respectively
...
In the body tube, the
eyepiece tube or draw tube holds the eye piece, where someone has to keep his eye
...
With the help of two adjusting screws, the body tube can
be drawn up and down
...
There are some lens attached with the nosepiece
...
Use of a compound microscope: To use the natural light for illumination of the object,
microscope should be set in a sufficiently lit place
...
The clips on the stage would be
placed on the slide to hold it properly
...
Using first the coarse adjustment screw
and then the fine adjustment screw, the object should have to be accurately brought
under the focus
...
If required, fine adjustment screw can be used to make vision more clear
...
Though it is little
hard, practice will make it easy
...
If the lens of higher power is required, moving the nosepiece, the expected lens can be
set to focus the object but in this case, students will obviously seek the help of a teacher
...
Procedure: Peel the dry scale leaves of an onion
...
After removing a small outer layer from the surface of the scale with the help of a
blade, put it in water in a watch glass
...
Leave a drop
of glycerin on the specimen object to observe and slowly place the cover slip on it
...
You will be able
to see rectangular and thin walled cells
...
In every cell, you will find thin, granular protoplasm, vacuole and a
sided nucleus
...
Essentials: Microscope, slide, cover slip, dropper, petriplate, pipette, glass rod, small
bowl of glass and water
...
Cut them into smaller
pieces and put the pieces in the water of the glass bowl and stir it steadily with a glass
rod
...
When the
things will be settled on the bottom of the bowl, draw some of the precipitation with a
pipette and put it on a petriplate
...
Observation: After searching for a while by moving the slide on two horizontal axes,
you will find some transparent, jel-like small organisms
...
Many
pseudo pods and vacuoles will be found in it and there will be a plasma lemma
surrounding the cell
...
Has there any
difference been found between a plant and an animal cell? Draw and label what you
have seen
...
What is a cell?
2
...
Show the relation between tissue and organ?
4
...
Which part of cell is called the ‘Power house’ of cell?
6
...
Describe the structure of a mitochondrion with labeled diagram
...
From a comparative point of view, discuss the structures and functions of
different types of simple tissue
...
Discuss the structures and functions of animal tissue
...
Which one is the function of lysosome?
a
...
to produce energy
c
...
to synthesize protein
2
...
well formed nucleus
ii
...
cell membrane
Which one is correct?
a) i and ii
b) i and iii
c) ii and iii
d) i, ii and iii
Biology
31
Read the flowing stem and answer the question 3 and 4:
On the way to his village house, Ruhit saw a man extracting fibers from a jute plant
...
What kind of tissue is being collected, mentioned in the stem above?
a
...
collenchyma
c
...
sclerenchyma
4
...
cell wall is lignified
ii
...
protoplasm is absent in the cell
Which one of the following answers is correct?
a
...
ii & iii
c
...
d
...
Figure- A
a)
b)
c)
d)
Figure- B
What is muscle tissue?
How skeletal tissue protects brain?
Explain the cause of location of Q marked part?
Between the pictures A and B, besides conduction in physiological activities,
mention what other roles does it play?
32
Biology
Chapter Three
Cell Division
Different types of cell division occur in all the types of organism from unicellular to
multi-cellular
...
In this chapter, you will know how the
different types of cell division occur
...
x Describe the types of cell division
...
x Describe the stages of mitosis
...
x Explain meiosis
...
x Understand the role of cell division in maintenance of the continuity of life
...
Life of every organism starts with a single cell
...
The increase of cells in number through
division is a very natural and important feature
...
They are called unicellular organisms, such as bacteria, amoebas, plasmodium
etc
...
Other organisms
are composed of more than one cell
...
Humans,
mango and Banyan trees etc
...
A giant Banyan tree also
initiates its structure after the formation of a single cell (zygote by the union of two
gametes)
...
Again, male and female gametes
are produced for the emergence of new generations
...
Types of cell division:
Three types of cell division take place in living body, such as, 1
...
Mitosis and
3
...
Amitosis: In this division the nucleus of a cell divides directly into two parts
...
The middle part of the nucleus narrowing continuously once
splits into two daughter nuclei
...
This type of cell division is found in bacteria, blue green algae, yeast etc
...
1 : Amitosis cell division
2
...
In this process, nucleus and chromosomes are
divided only once and two identical daughter cells are produced with the same type
of chromosomes in number, physical and structural features as their mother cell
contains
...
The process
usually take place in the body cells of animals and in the meristems of the plant
parts growing, such as the tip of stems and roots, plumule and radicle, developing
leaves, buds etc
...
During mitosis,
karyokinesis is usually followed by cytokinesis
...
Before the starting of
the cell division, a cell has to prepare itself
...
For the ease
of description, the process mitosis can be divided into five stages
...
At the onset of the stage, nucleus becomes
little larger and chromatin fibers start condensing into short, thick and tightly coiled
structures called chromosomes
...
Though every chromosome then divides into two sister chromatids, at the
centromere each one remains together
...
Figure: 3
...
The middle plane
of the spindle apparatus is called equator
...
They are called spindle fibers
...
Kinetochores are protein structures assembled on
centromeres and link the chromosomes with mitotic spindles
...
They are also called chromosomal fiber as
chromosomes are attached with them
...
The nuclear membrane and nucleolus being disintegrated begin to
Biology
35
disappear
...
(c) Metaphase: At the onset of the stage, all the chromosomes complete their
assembling at the equator, middle plane from the two poles
...
In this stage, chromosomes look most short and thick
...
At the late of the stage, division of
centromere starts
...
(d) Anaphase: The sister chromatids become the two sister chromosomes and they are
pulled apart
...
Each chromosome splitting into two moves to two poles, and so the
number of chromosome remains unchanged
...
At the
end of the stage anaphase, the daughter chromosomes are totally pulled to the two
poles and start their elongation
...
Chromosomes
being decondensed and surrounded by new nuclei elongate back into thin and long
structures called chromatin fibers
...
So, ultimately, two new
nuclei are formed in two poles
...
Figure : 3
...
Metaphase
36
Biology
At the end of the stage telophase, some small parts from endoplasmic reticulum
aggregate in the equatorial plane and collectively form the structure cell plate
...
As a result, two identical
daughter cells are developed
...
Significance of mitosis
The significance of mitosis in the living body of organisms is immense
...
Through mitosis, the growth in the body
multicellular organisms occurs
...
The repeated division of this single cell produces innumerable cells and thus an
organism grows to its complete level
...
Mitosis plays a role in maintenance of normal size, shape and volume of
cells
...
Mitosis plays an important role in
the vegetative reproduction of organisms and increasing the number of reproductive cells
...
The life span of some cells is specific and they are,
accordingly, replaced through the process of mitosis
...
Mitotic errors
may result in abnormal mass of cells called tumours, with or without cancer cells
...
Meiosis: In this special process of cell division, four daughter cells are produced from
an eukaryotic cell
...
As the number of chromosome decreases by half, the process of cell division is called
reductional division
...
In process mitosis, the number of chromosomes in
the daughter cells remains the same as that of their mother cell
...
In sexual reproduction, the union of
male and female gametes is required
...
Supposing the number of chromosomes
in a vegetative and a reproductive cell of an organism is 4
...
If every life cycle
of an organism continues that way, the number of chromosome would be doubled again
and again
...
If the number of chromosome is increased life
cycle after life cycle, the offspring will be basically different
...
When at the time of the
development of reproductive cells and in any stage of the life cycle of plants in lower
groups, the process meiosis occurs, then the feature of possessing half number of
chromosome is called haploid
...
As the meiosis cell division occurs, the
features in the species of living organisms keep
on the same more or less, generation after
generation
...
In the anthers and ovules of flowering
Figure: 3
...
During the development of pollens from diploid pollen mother cells in
mosses and ferns, meiosis occurs in their
zygotes
...
The first and the second
division are called meiosis-1 and meiosis-II
respectively
...
8 concept of meiosis cell division
38
Biology
the second division is simply a mitosis
...
So
generation after generation, the number of chromosomes remains the same in the cells of
the body of offspring
...
Exercise
Short answer question
1
...
What is equational cell division?
3
...
Describe the different stages of mitosis with the labeled diagrams
...
Discuss the significance of mitosis
...
In which stage, does a nucleus become larger?
a
...
metaphase
c
...
telophase
2
...
the number of chromosomes is changed
...
haploid gametes are developed
...
consistency of features in organisms is maintained
...
i &ii
b
...
i & iii
d
...
Figure-1
Figure- 2
3
...
the mother cell and the daughter cells bear same features
...
the number of chromosome becomes half in the newly developed cell
...
chromosomes divide once
...
i & ii
b
...
i & iii
d
...
The division in the figure B is different form that of the figure A and soa
...
b
...
c
...
d
...
Creative question
...
Stage-A
a
...
c
...
Stage-B
Where does amitosis occur?
Write in detail why meiosis is called the reductional division
...
Explain what problems may emerge if the process expressed in the figures above
does not accomplish properly
...
For these reactions, energy is somewhat required
...
The green plants transforming solar energy into
chemical energy produce the food carbohydrates through the process of photosynthesis
...
They have to
depend somehow on green plants for the energy they require for the maintenance of their
life
...
In this chapter, these cellular processes are discussed
...
x Explain the production of carbohydrates through the process of photosynthesis
...
x Describe the role of factors in photosynthesis
...
x Explain respiration
...
x Draw comparisons between photosynthesis and respiration
...
x Understand the contribution of plants in preparing food for organisms and learn
conscious behaviors towards plants
...
The sun is the main source of energy
...
These are the bioenergy
of life
...
For the regulation of
life, thousands of chemical reactions occur in living cells and so in the living bodies
...
Some energy-rich compounds contain high energy and in necessity provide other
chemical reactions with energy, such as ATP, GTP, NAD, NADP, FADH2 etc
...
This is why ATP
is called biological coin or energy coin
...
This process is called photophosphorilation
...
ATP is the carrier of free energy, and energy is organised in its phosphate bonds
...
Photosynthesis
An important feature of green plants is that they produce food carbohydrates from
carbon dioxide and water in presence of sunlight
...
In this process, light energy is
transformed into chemical energy
...
The existence of mankind and other living creatures
depends on the foods produced and stored in plants
...
Photosynthesis is a biochemical reaction mentioned below:
light
C6H12O6 + 6H2O + 6O2
6CO2 + 12H2O
chlorophyll
The mesophyll tissue of a leaf is the main place of occurrence of photosynthesis
...
Aquatic plants absorb CO2 which is dissolved
in water
...
03% and 0
...
So, the rate of photosynthesis is higher in aquatic plants than that of land plants
...
1 Photosynthesis
Oxygen and water are the by-products of photosynthesis
...
In this process H2O is oxidised and CO2 is reduced
...
In 1905, British physiologist Blakmann
divided the process into two phases
...
(1) Light dependent phase: The energy light is essential in the light dependent phase
of photosynthesis
...
Through this process ATP (Adenosine triphosphate) and NADPH+H+ (reduced
nicotinamide adenine dinucleotide phosphate) are produced
...
The chlorophyll molecules absorb photons from light and with the
help of the energy obtained from the photon absorbed, ATP is formed by the
addition of an inorganic phosphate with ADP
...
light
ADP + Pi
ATP
chlorophyll
Oxygen, hydrogen and electrons are evolved through the hydrolysis of water with the
help of sunlight and chlorophyll
...
ATP is produced by the process of photophosphorilation and the electrons reduce
NADP, and produce NADPH+H+
...
Biology
43
Light independent phase or dark phase:
No light is directly required in the light independent phase, but the process can be
carried out in the presence of light
...
In
the green plants, the pathways of CO2 reduction have been identified, and they are
briefly discussed here, such as, (1) Calvin cycle (2) Hatch & Slack cycle and
Crassulacean acid metabolism (CAM)
...
(1) C3 cycle or Calvin cycle:
Atmospheric CO2 enters the cells through the stomata of the leaves
...
Immediately this unstable
compound is broken down and two molecules of 3 Phosphoglyceric acid are formed
...
Using ATP and NADPH+H+
produced in the light phase, 3 Phosphoglyceric acid is transformed into 3
Phosphoglycereldehyde and dihydroxyacetone phosphate
...
Resynthesised ribulose 1,5
bisphosphate mixing with a molecule of CO2 enters Calvin cycle
...
The pathway of fixing CO2 is named after its discoverers’ names Calvin-BensonBassham (CBB) cycle or simply Calvin cycle
...
In most of the plants, carbohydrates are produced through
this process
...
(2) C4 cycle or Hatch-Slack pathway:
In 1966, two Australian scientists
...
D
...
R
...
The first stable substance formed in the pathway is 4-carbon
Oxaloacetic acid
...
The rate of photosynthesis in C4 plants is higher than that of in C3 plants
...
Role of chlorophyll in photosynthesis:
There is a direct relationship between the rate of photosynthesis and the amount of
chlorophyll in the leaves because only chlorophyll can capture solar energy
...
Photosynthesis is dependent on the rate of regeneration of chloroplasts or the
components of chloroplasts
...
But, too much chlorophyll in the cell results in the shortage of enzymes and the rate of
photosynthesis comes down
...
For the production of
carbohydrates from H2O and CO2, the source of required energy is light
...
With the effects of sunlight and stomata being
opened, CO2 can enter leaves, and take part in the production of food carbohydrates
...
Red, blue, orange
and purple portions of visible spectrum function better than that of green and yellow
...
If
the amount of light increases too much, enzymes, being disintegrated, cause the
production of chlorophyll to get lower, and consequently the rate of photosynthesis also
decreases
...
Factors affecting photosynthesis:
Besides light and chlorophyll, photosynthesis is also affected by some other factors
...
Presence and absence, less
or more amount of factor affect the total amount of photosynthesis
...
(a) External factors:
Light: It has already been discussed little earlier
...
The food produced by this process is formed from the reduction of carbon
dioxide
...
03% but in this process,
plants can use carbon dioxide up to 1% concentration
...
If the
amount of carbon dioxide is increased to a very high level, acidic condition in the cells
of mesophyll tissue increases and stomata get closed, so the rate of photosynthesis,
ultimately, decreases
...
At a very low temperature (around 00C) and a very high temperature
(above 450C), the process photosynthesis cannot be carried out
...
If temperature remains below 220C
or above 350C, the rate of photosynthesis will decrease
...
In scarcity
of water, guard cells of stomata become flaccid, and so, the entry of CO2 is disrupted
...
Oxygen: If the concentration of oxygen increases in atmosphere, the rate of photosynthesis
decreases and conversely, the rate of photosynthesis increases with the decrease of oxygen in
atmosphere
...
Mineral nutrient elements: Nitrogen and magnesium are two main components of
chlorophyll
...
Thus, the rate of photosynthesis decreases at the low level of
minerals in the soil
...
Internal factors:
Age and number of leaves: Too young or too old leaves contain very little amount of
chlorophyll
...
With the aging
of leaves, number of chloroplasts also increases
...
With the increase of the number of leaves, the rate of
photosynthesis is accelerated
...
In the evening, the rate
of photosynthesis is low because of the accumulation of carbohydrates produced earlier
...
Enzymes: Lots of enzymes are required for the process of photosynthesis
...
Through the
process, a bridge is developed between the life and the sunlight
...
The foods we eat such as rice, bread, fruits, vegetables, fish, meat, milk,
egg etc
...
So, all the form of animals
are completely dependent on green plants for their food, and the green plants produce the
food through the process of photosynthesis
...
For maintaining the balance of different components in the atmosphere, especially the
ratio of CO2 and O2, photosynthesis is very important since this process maintains the
crucial balance
...
95% and 0
...
46
Biology
For the normal growth and survival of plants and animals on earth, these two gases
should be present in atmosphere within normal limit
...
We
know that the cellular respiration is taking place in all living organisms (with plants or
animals) all the time
...
If only
respiration would have occurred in nature, the shortage of O2 and the predominance of
CO2 would definitely be found in atmosphere
...
Nowadays, an alarming situation of changing the ratio
between the two gases has been apprehended for cutting down plants and trees in excess,
and so, we should massively plant trees
...
Foods, clothes, industrial materials
(such as nylon, rayon, paper, cellulose, timber, rubber), medicine (such as quinine,
morphine), fuel coal, petrol, gas are produced from plants
...
This is
why photosynthesis is the most important biochemical process in the living world
...
Essentials: A potted plant with leaves kept in dark for one day, black paper, 95% ethyl
alcohol, 1% iodine solution, paper clips
...
Then, the potted plant will be kept in sunlight for an hour to decolourise the
cholorphyll of that part
...
Now the boiled
and decolourised leaf will be drained with iodine
...
Conclusion: For the chemical reaction between starch and iodine, starch will turn blue
(the deep purple or black)
...
As starch is not
formed in that part of the leaf, it cannot turn blue
...
Biology
47
Precautions
(1) Before the performing of the experiment, the potted plant should be kept in dark for
sometime (about 48 hours)
...
Before the time of performing the test, the potted plant should be kept in sunlight at least
for an hour
...
In this chapter, little more detailed discussion will be made on respiration
...
The main source of
energy is the sun
...
The stored energy in the food cannot
be directly used by the organisms for the maintenance of their life
...
This kinetic energy
provides all the organisms with the energy they require to perform all of their
physiological activities
...
These complex compounds in the bodies of living
organisms, are broken down into simple compounds before releasing energy and later
being reduced these compounds are transformed into ATP
...
But, at the growing
parts of a plant such as in floral and lateral buds, germinating seeds, tip of stem and root,
the rate of transpiration is very high
...
In this physiological process, organisms, oxidising the
complex organic compound into simple substance, produce energy
...
different enzymes
6CO2+ 6H2O + Engergy (688k cal/mol)
C6H12O6 + 6O2
Glucose
Types of respiration
On the basis of the availability of oxygen during respiration, the process is divided into
two types: (1) Aerobic respiration (2) Anaerobic respiration
...
Aerobic respiration is the normal respiratory process of plants
and animals
...
different enzymes
6CO2 + 6H2O + energy (688 K
...
C6H12O6 + 6O2
Through the aerobic respiration, a molecule of glucose being completely
oxidised produces energy, six molecules of CO2, 6 molecules of H2O and
38 molecules of ATP
...
That is, in anaerobic respiration, respiratory substances being
partially oxidised with the help of enzymes, produce different types of organic
compounds (ethyl alcohol, lactic acid etc
...
2C2H5OH + 2CO2 + energy (55 k cal /mol)
C6H12O6
glucose
ethyl alcohol
Only in some microorganisms such as in bacteria, yeast etc
...
Short description of aerobic respiration
Aerobic respiration is generally divided into four distinct stages:
Stage 1: Glycolysis
Through many chemical reactions, a molecule of glucose (C6H12O6) is broken down into
two molecules of pyruvic acid (C3H4O3)
...
As, in this process, no oxygen is required, it
is the initial stage for both the aerobic and anaerobic respiration
...
Stage-2: Acetyl co-A formation
Each molecule of pyruvic acid, produced in glycolysis after the consecutive reactions, is
transformed into a molecule of 2-carbon acetyl co-A, a molecule of CO2 and a molecule
of NADH+H+ (from two molecules of pyruvic acid two molecules of acetyl coenzymeA, two molecules of CO2 and two molecules of NADH+H+ are produced
...
The cycle is named after the name of a British biochemist Sir Hans Kreb since he
discovered the cycle
...
All the reactions of this cycle occur in the mitochondria
...
So, from two molecules of
acetyl co-A, four molecules of CO2, 6 molecules of NADH+H+, two molecules FADH2
and two molecules of GTP are produced
...
The energy
is released at the time of passing of electrons containing high-energy through the
electron transport system
...
Electron transport
system is constituted in the mitochondria
...
3 Respiratory process
In aerobic respiration, a molecule of glucose being completely oxidized, produces six
molecules of CO2, six molecules of water and 38 ATP
...
used substance Neat product
stage of respiration substance produced
Glycolysis
2 molecules pyruvic acid
4 molecules ATP
2 ATP
2 ATP
2 NADH+H+
6 ATP
Acetyl Co-a
2 acetyl coA
2 pyruvic acid
2 CO2
6 ATP
2 CO2
2 NADH+H+
Kreb’s Cycle
4 CO2
2 acetyl co-A
4 CO2
6 NADH+H+
18 ATP
2 FADH2
4 ATP
2 ATP
2ATP
38 ATP (neat
total ATP)
+
1 NADH+H = 3 ATP
1 FADH2 = 2 ATP
1 GTP = 1 ATP
50
Biology
Stages of anaerobic respiration:
Anaerobic respiration is constituted of two stages
...
It is the same as the glycolysis stage of aerobic respiration
...
With the help of enzymes in cytoplasm, pyruvic acid, being incompletely oxidized,
produces CO2 and ethyl alcohol or only lactic acid
...
This process helps plants to absorb mineral salts, which indirectly drive the
growth and other physiological activities in a plant
...
So, this process
also controls the growth of organisms
...
Some
bacteria cannot live in presence of oxygen
...
Through the process, ethyl alcohol is produced and this process is used in
industry
...
It is
also used in making bread
...
CO2 makes the bread inflated or swelled
...
(a) External factors: External factors affecting respiration are mentioned below
...
The optimum temperature for respiration is from 200C to 400C
...
So, aerobic
respiration cannot be carried out in any way without oxygen
...
If the supply of water decreases or increases too much, the process
respiration is inhibited
...
Carbon dioxide: If the amount of CO2 is increased in the air, the rate of respiration
becomes little slower
...
Enzymes: Many types of enzymes actively take part in the process of respiration
...
Age of cells: In young cells, especially, cells in the meristematic tissue, the amount of
protoplasm is enough to cause respiration at a higher speed in them than that of old cells
...
Work: Experiment to demonstrate the release of energy in the form of heat during respiration
...
Figure: Picture of thermos flasks
...
With some water
some germinated chick peas would be taken in thermos flask ‘A’
...
The remaining chickpeas will be taken in flask B after boiling them soaking in
10% mercuric chloride solution for 10 minutes
...
Observation:
The temperature of the thermos flask, containing germinated seed, will be marked A
rises but there would be no thermal change in the other flask having seeds being
inactivated with mercuric chloride
...
But, in the
thermos flask ‘B’, the seeds being dead for soaking and boiling them in mercuric
chloride solution, no heat was evolved because of the ceasing of respiration in them
...
The seeds should be fresh and well germinated
...
The tip of the thermometer containing mercury should be positioned at the
middle of the stacked of seeds
...
What is photosynthesis? Represent it by a chemical equation
...
What are the raw materials for photosynthesis?
3
...
4
...
5
...
Essay type question
1
...
2
...
Multiple choice questions
1
...
Water
b
...
Oxygen
d
...
What number of ATP is produced in the glycolysis stage of respiration
...
4
b
...
8
d
...
3 and 4
...
The functions of both A and B are –
i
...
To release H2O
iii
...
i & ii
b
...
ii & iii
d
...
The process accomplished in the figure Xi
...
to help the process of photosynthesis
iii
...
Which one of the following is correct?
a
...
i & iii
c
...
i, ii & iii
Creative Question
1
...
b
...
d
...
a
...
c
...
What will be the effects on plants if the production of A is inhibited? Explain with
logic
...
As the carrot contains glucose, it
provides her with energy
...
She replies her sister that a plant also derives energy through the
process respiration
...
What will be the effects on plants if the process mentioned above is inhibited?
54
Biology
Chapter Five
Food, Nutrition and Digestion
Living organisms live on food that means food is essential to live in
...
Different elements are necessary for
plant’s nutrition
...
At the end of this chapter, we will be able to –
x Explain the necessity of essential elements for plant nutrition
...
x Describe main components of animal foods and its sources
...
x Explain kilo calorie and kilo joule
x Explain the amount of energy in nutrients and conversion of calorie and joule
...
x Determine the relation between BMR and energy spent
...
x Explain importance of exercise and rest for good health
...
x Describe the organs of the alimentary canal along with accessory glands
...
x Explain the functions of pancreas
...
x Explain different intestinal diseases, symptoms, remedy and prevention
...
x Draw a poster regarding the contribution of nutrition to healthy living to raise awareness
among people
...
x Be conscious myself and others of the family about intestinal diseases for healthy living
...
Biology
55
Food, Nutrition and Digestion
Plant’s mineral nutrition
Plant mineral nutrition: The nutrient, which a plant receives from soil and its
environment for its normal growth, physiological activities, reproduction, is plant
nutrition
...
About 60 inorganic nutritional elements have been identified in plants
...
These
16 nutrient elements are collectively called essential elements because they are required
for the normal growth, physiological activities and reproduction of all types of plants
...
The necessity of an element cannot be substituted for another element
...
On the basis of the amount of essential mineral nutrition
consumed by plants, nutrient elements are divided into two groups: macro-nutrient or
macro-element and micro-nutrient or micro-element
...
Plants use 9 macronutrients or macro-elements and they are nitrogen (N),
potassium (K), phosphorus (P), calcium (Ca), magnesium (Mg), carbon (C), hydrogen
(H), oxygen (O) and sulfur (S)
...
Plants use 7 micronutrients and they are zinc (Zn), manganese (Mn), iron
(Fe), molybdenum (Mo), boron (B), copper (Cu) and chlorine (cl)
...
Other
elements are taken from soil by the absorption of roots
...
Plants cannot directly absorb them as slats
...
Role of different mineral elements in plant nutrition: Mineral nutrition plays a very
important role for the normal growth of plants
...
If the formation of chlorophyll is hindered, the
production of food will be affected
...
Magnesium is one of the chemical
components of chlorophyll molecule
...
In closing and opening of stomata, the role of
potassium is immense
...
It
also helps plants in developing and growing of root, flower and fruits
...
Phosphorous is the structural
component of DNA, RNA and ATP in living cells
...
For their role in nutrition, chemical fertilizers such as urea for
nitrogen, muriate of potash for potassium chloride, triple super phosphate for
phosphorus are used in the cultivating fields for high yield
...
Nitrogen is the essential element of nucleic acids,
proteins and chlorophyll
...
Phosphorous is the important
structural element of nucleic acids, different phospholipids, NADP and ATP
...
Potassium helps a
plant to absorb water
...
In
addition, it helps the development and growth of roots, flower and fruits
...
Iron is the structural component of cytochrome, and so it is required for aerobic
respiration
...
Manganese is needed to construct and maintain chloroplasts
...
Boron is required for the active growing regions of plants, and it also
plays a role in the conduction of sugar
...
It is required little for the general metabolic activities of plants
...
For the growth
of root and stem of sugar beet, chlorine is a prime need
...
These symptoms are called deficiency
symptoms
...
Some deficiency symptoms of some nutrient elements are mentioned below
...
Leaves turn yellow
...
Growth and division of cell is
decreased and ultimately the total growth of a plant is reduced
...
Necrotic spots are developed in leaves
...
The plant becomes stunted for the growth being
stopped
...
Growth of plant is reduced, and apical and
lateral buds become dead
...
At the time of flowering in plants,
stems are dried up and the plants get wilted
...
Chlorosis occurs deeply and rapidly in the middle places of veins
...
Sometimes
the whole leaf becomes pale
...
Sulfur
(S)
Leaves show overall a general chlorosis, and reddish and purple spots
appear on them
...
The tips of stem die and die back disease is caused
...
Boron
(B)
Necrosis of meristematic tissue in growing regions occurs in deficiency
of boron
...
The
initiation of floral bud is obstructed
...
Animals’ food and nutrition: In the meantime you have learnt in class six and eight
that food is essential for life, exactly same balanced diet is necessary for good health
...
So combustion means the production of heat and energy by chemical reaction
...
For moving, playing and doing other works energy is necessary
...
The substances which are digested and absorbed within the body and that
help in repairing, producing heat and growth of energy and helps in repairing, staying
healthy, supplies nourishment for vital activities, protect from diseases and produce heat
and energy, are called food
...
For performing these tasks properly different types of food is necessary
...
These chemical substances are the
ingredients of food
...
So these are called
nutritional ingredients
...
Food may
contain more than one ingredient, the food is classified into the name of the ingredient
which is more present in the food then any other ingredients
...
Protein: For growth and repair
...
Carbohydrates: Helps in producing energy
...
Fat and oils: Produces heat and energy
...
as :
58
Biology
1
...
2
...
3
...
Regulates the cell activity and
contains the organelles
...
Protein contains
20% of nitrogen
...
Due to
the presence of nitrogen, sulpher, phosphorus and iron the importance of proteins is
different from carbohydrates and fats
...
Only protein is the source
of nitrogen
...
Sources of Protein : We have learned earlier, that
we get proteins from fish, meat, eggs, milk, pulse,
drilled fish, bean seed, nuts etc
...
Animal protein: Fish, meat, eggs, cheese, posset, liver are the sources of animal protein
...
So they are considered first
class protein or high class protein
...
At least
20% percent of animal protein should be in our food menu
...
These are less nutritious, because plant protein does not contain all the essential
amino acids
...
The
energy value of plant protein is less
...
Through researches it is proved that if two or more plant proteins are cooked together, as
a result of the increase of food value eight kinds of amino acid can be obtained from it
...
It is also called
supplementary protein
...
Preparation of rice porridge or paesh
...
Food prepared by boiling rice and dal
...
Preparation of ‘halim’ with the mixture of dal, wheat and meal
...
To serve fish and dal with rice
...
Eating bread and milk
...
Eating bread and dal
...
A supplementary protein can be prepared from different varieties of mixed dals
...
It is composed of
carbon, hydrogen and oxygen
...
Glucose in fruit juice, lactose in milk, starch in wheat, potato,
Biology
59
rice etc are different forms of carbohydrates
...
Formation and composition of three types of
carbohydrates are shown in the table given below
...
2)
Table 10
...
Carbohydrates
Composition
Example
Sources
Mono-saccaride
One
molecule
glucose
of Glucose
Honey, fruit juice
...
Sugar and milk
...
leaf, vegetables
...
In raw form carbohydrates can
not be easily digested
...
After taking carbohydrates is digested and turns into glucose
...
For human nutrition simple carbohydrates are very important
...
Fats: Fat is an essential component of food
...
It
remains in the stomach for a long time, so we do not
feel hungry
...
It is also
stored in various organs, as – liver, brain and
muscles
...
It contains two time calorie than carbohydrates and
Figure: 5
...
Calorie is the measuring unit of energy in food
...
At the same time it also
increases the nutritional value
...
Some fats
contain vitamin ‘A’, some contains vitamin ‘E’
...
As – 1)
Vegetable fat and 2) Animal fats
...
Soyabean oil is the best one
...
are animal fats
...
Fats are insoluble in water
...
Daily
requirement of healthy adult person needs 50-60 gm
...
3 Fats and ruls
60
Biology
Vitamins: Very minute amount of vitamins is needed for health; even then its
importance is unbounded
...
Balanced diet contains different types of ingredients, so sufficient vitamins
can be obtained from balanced diet
...
Afterwards, it may cause severe harmful
effects on the body and even death
...
As : 1) Fat soluble
vitamins and 2) Water soluble vitamins
...
Vitamin ‘A’ is obtained from milk, butter, fats, eggs, carrot, mango, jack fruit, colored
vegetables and mola, dehela fishes, yeast
...
g
...
Vitamin ‘C’ is obtained from
Guava, pomelo, star fruit, orange, cabbage, tomato, pineapple, green chilli, fresh
vegetables etc
...
Vitamin ‘E’ and vitamin ‘K’ can be obtained from all the above mentioned
foods
...
Human body contains mineral salts, such as: calcium, iron, salphur, zinc, sodium,
potassium, iodine etc
...
These elements
remain within the food and human body as a compound with other elements
...
Mineral salts
regulate body building and internal functions
...
It has a particular role in nerve impulses, muscle contraction, maintains
water balance in body cells, balancing of acid and base etc
...
Liver, green
vegetables, meal, yolk, arum leaves contain iron
...
Table salt, chips, salty food, cheese, nuts, pickles etc
...
Fish, meat, nuts, pulses, banana, potatoes, carrots, apples etc contain potassium
...
The sources of iodine are sea weeds,
sea fish, meat and algae
...
For the existence of life the position of water is just
after oxygen
...
Body building and
internal functions can not continue without water
...
(1) Body formation: Body formation and maintenance can not be possible without
water
...
Biology
61
(2) Control of internal functions: No chemical reaction can occur inside the body
without water
...
Blood transport is possible only because of water
...
Digested food products are absorbed
by the blood from small intestine
...
Sufficient
water goes out of the body, with urine, stools, sweat etc
...
Demand of water for the
body depends on age, labour, food habit and environmental condition
...
Such as : a man who’s daily calorie
demand is 2000 (kcal) Kilocalorie, then he needs 2 liter of water daily
...
Basically these are cellulose and
lignin of cell walls
...
These are complex carbohydrates
...
Roughage absorbs water, increases the
amount of faces helps to eliminate stools
...
It is assumed that roughage reduces of cancer to some
extent
...
An ideal food pyramid
Any balanced diet includes carbohydrates, vegetables, fruits, protein, fats or oils
...
Placing carbohydrates at the
base line and considering the quantity of vegetables, fruits, proteins, fats and oils
successively, if we arrange these food substances in successive tiers, it shows the
presence of fats and oil at the highest
...
This is
called ideal food pyramid
...
The necessary foods, that we take daily, are shown in the form of pyramid
...
We take
carbohydrate in a large quantity such as: rice, potatoes, bread etc
...
Fish, meat, eggs, milk, pulses, cheese, posset, curds should be taken in
lesser quantity
...
We have to choose
diet according to the food pyramid, and then we will able to select a balanced diet
...
This habit is not good for sound health
...
Accordingly we are to follow the
rules of taking food in time
...
Every body should know the rules
of healthy eating because if the rules are
known thoroughly, then it is easy to fulfill
the demand of every family members by
having knowledge of food selection, food
calorie, family income etc
...
Figure-5
...
A man should have the adequate ability to produce energy through metabolism
...
In diet the ratio of protein, fats and carbohydrates should be 4:1:1
...
Inclusion of fresh fruits and vegetables in balanced diet for the supply of
necessary vitamins, roughage or cellulose
...
There must be sufficient amount of water and mineral
...
Balanced diet must be easily digestible
...
For a well
developed body it is an important task to make a food chart or menu by including foods
that contain six ingredients
...
These are the demands of the body, easy availability and family income
...
The mentality of selecting low cost food, that contains equal food
value instead of costly food, is a good practice
...
It is essential to be specially careful about some
matters
...
x Knowledge about food value
...
x Presence of adequate amount of vitamins, minerals and water
...
x Economic condition of the family and number of family members
...
You will get knowledge about the demand of
calorie and amount of food needed for the male and female persons of different age
...
Adult male
Adult female
Name of food
grains
Without
work
(gm)
Moderate
working
(gm)
Hard
working
(gm)
Without
work
(gm)
Moderate
working
(gm)
Hard
working
(gm)
Bean/kidney
bean
20
25
30
20
22
...
This is published and accepted by the Institute of Nutrition and Food
Science (INF s, 1975)
...
edible part has been determined
...
4
0
...
7
79
...
1
1
...
7
69
...
1
5
...
0
60
...
1
0
...
1
56
...
9
0
...
1
10
...
6
0
...
6
22
...
9
0
...
1
3
...
0
0
...
7
2
...
1
1
...
4
10
...
4
0
...
3
4
...
6
0
...
0
4
...
8
0
...
6
4
...
5
0
...
0
3
...
2
0
...
4
15
...
8
19
...
2
2
...
5
2
...
5
2
...
1
1
...
7
0
...
6
2
...
0
-
114
Egg
13
...
3
1
...
9
0
...
3
-
109
Mutton
18
...
3
1
...
2
4
...
8
4
...
1
3
...
1
7
...
00
-
-
900
Cooking oil
-
100
...
¾ Drink 7-8 glass of water daily
...
¾ Make a habit of taking seasonal fruits, fresh vegetables
...
Avoid canned and frozen vegetables
...
Vitamin deficiency diseases:
Goiter : Goiter is a disease of thyroid gland
...
When thyroid gland abnormally enlarges due to the
deficiency of iodine
...
Goiter is of two types
...
Biology
65
(1) Simple goiter: Simple goiter: Due to the deficiency of iodine, thyroid gland swells or
one of two glands swells
...
This is simple goiter
...
The thyroid gland of the patient swells and he feels troubles in respiration
...
(2) Toxic goiter: The cause of this disease is over secretion of thyroxin
...
According to doctor’s advice the growth of the
gland can be resisted or blocked
...
e
...
sea weed, sea fish
etc
...
Generally 2-5 years children suffer from this disease
...
The patient can not see in dim light
...
If the disease aggravates, the cornea turns dull
...
Vitamin ‘A’ enriched food, such as : fish liver oil, lever, green vegetables,
coloured fruits (ripe mango, banana, sweet pumpkin, carrot etc) and eating mola and
dehla fish, feed vitamin ‘A’ capsule if necessary
...
Rickets: This is not a viral or bacterial disease
...
This vitamin is essential for the absorption of calcium and phosphorous in the
intestine, formation of teeth and bones
...
Human skin can produce vitamin ‘D’ by the influence of sunlight
...
Besides, this structure of the body can not be
kept in a proper order, bones become brittle and thorax turns narrow
...
So vitamin is
produced by the influence of ultra violet rays of the sun light
...
The
deficiency of iron based protein is the general cause of anemia in Bangladesh
...
There may be various causes of
having iron deficiency anemia
...
Under aged children suffer much
66
Biology
from iron deficiency
...
To prevent from this disease taking of iron enriched food
...
After ensuring the infection of
worms in the intestine through tests, the patient needs to take worm destroying drugs
...
Work: Draw a poster regarding the contribution of nutrition to healthy living
...
But do we know what amount of food
gives us what amount of energy? Is the elimination of energy from different nutrients
same? Among the six nutrients only proteins, carbohydrates and fats can produce
energy
...
You know, energy is of various types
...
Unit of heat
energy is calorie
...
A calorie is defined
as heat to raise one kilogram of water to one degree centigrade
...
But generally nutritionist terms it as calorie
...
The more energy
will be spent, the more the muscles will contract or expand
...
We feel easy to do any work because of muscles
...
How much energy is spent to do this type of
works?
Energy is required for the contraction and relaxation of muscles
...
The consumption of energy
depends on work
...
We feel less energy is spent in resting time
...
But in our
respiration, heart works as usual
...
So all the muscles, involved in these functions, contract and relax to perform
the work as a whole
...
This energy is called basic
metabolic energy
...
(1) Basic metabolic rate (2) Type of daily physical labour and (3) Influence of food
...
1000 kilo joule
=
1 mega joule
...
=
4
...
1 mega joule =
...
Example :
2800 kilo calorie
=
How much joule?
2800 kilo calorie
=
2800 × 4180 joule
...
18 kilo joule
...
7 kilo joule
...
In this case 1000 kilo calorie = 4
...
To determine heat energy in food nutrients
Every day we take different types of nutrients
...
So to measure the amount
of energy of the nutrients we have to know about the nature of the foods
...
Mixed food contains more than
one nutrient
...
g
...
on the other hand the single food
contains only one nutrient
...
g
...
It contains only carbohydrate
...
So we should know which food contains what nutrients and its amount
...
Determining calorie
After knowing the ingredients of the nutrients and its amount, we have to calculate the
calorie of carbohydrates, protein, fats
...
Let us determine the calorie of
20 gms of chira
...
4 gm carbon (77%)
1
...
24 gm fats (1
...
4 gm carbon × 4 = 61
...
1
...
28 calorie
...
24 gm fat × 9 = 2
...
Therefore the whole amount = 69
...
So, calorie value of 1kg of chirra
=
69
...
00 calorie
...
1000 kilocalorie = 4
...
Therefore, 3452 calorie = 14
...
Basic metabolic rate (BMR) and Basic metabolic Index (BMI): Basic metabolic rate
indicates the used energy of human being at resting stage
...
So basic metabolic index indicates the relation
between the length and deposition of the fat of a person of particular age for healthy
living and maintaining good health
...
Determining BMR value
To calculate BMR value is a bit difficult, its equations are different in case of male and female
...
BMR (female) = 655 + (9
...
kg) + (1
...
cm) – (4
...
year)
BMR (male) 66+(13
...
Kg) + (5 × height
...
8 × age
...
So, her BMR = 655 + (9
...
8 × 165) – (4
...
4 + 297 + 155
...
3 calorie
...
Physical condition
Calorie
Not working
BMR value × 1
...
Playing 2-3 days in a week
...
375
Working, sufficient playing 2-3 days in a week
...
55
Working, playing everyday in a week
...
725
Hard working, sufficient jumping, running and playing
...
9
Example: It is assumed this woman is not working
...
3, so her calorie
demand is (1699
...
2) or 239
...
So by taking 2039 calorie this woman can maintain
same weight
...
BMR value has a control on the production of 60-75
percent energy
...
BMR value declines with the increasing of
age
...
So BMR value declines more
...
BMR can be raised or increased by adequate
physical work
...
Determining BMI value:
BMI = Body wt (kg)/ height of the body
...
25 meter) height and 50 kg weight, has 32 BMI
...
5, has to increase body weight by taking adequate food
...
5 – 24
...
25 – 29
...
30 – 34
...
Physical work and selection of food is necessary
...
9: second stage of obesity
...
Above 40: the extreme stage of obesity, Possibility of death risk, doctor’s advice is
necessary
...
So body weight
can be controlled by taking inaccurate nutrition and exercise
...
Now adays obesity
increases due to the scarcity of play ground, nature of work, educational pressure, less
physical works are the main causes of our obesity
...
So body remains strong which means sound health
...
It is found that a long and healthy living
is possible by practicing an hour moderate work and taking in adequate food
...
One can get relief form diabetes,
heart diseases and some kind of cancer through physical exercise
...
Such as: athletics, exercise that makes
bones and muscles strong and stout
...
Rest is very important for health
...
Lie
down and sleeping is a part of rest
...
You will be astonished to know that almost all animals in the living world
take rest
...
Many animals are active in
sunlight
...
These are nocturnal
...
As a result the
properties, acceptability, food value remain intact
...
70
Biology
Fish drying, salted Hilsha, pickle, ice preservation, fish sidol, prawn naptae etc are the
customary means of food preservation
...
Healthy, approved chemical
substances are used to preserve food so that decomposing bacteria and fungal infection
may not happen
...
g
...
These are approved chemicals
...
Adulterant in food and use of colours
As clear environment is necessary to live in the beautiful world, similarly safe food stuff
is essential
...
As a result public health is
now threatened
...
Bangladeshi
nation will be vanished just like the Romans
...
By any means, people, who drank that water, were affected by poisonous lead and
cripple generation took birth
...
Commercial colors, antibiotic, chemical substances (e
...
sorbet, carbide,
insecticide, pesticide, formalin, heavy metal) are mentionable
...
These adulterant foods are injurious to health
...
Commercial colour that is used in textile or for colouring, that
is used in ice-cream, blended ice cream, candies, beguni, bora etc
...
Decomposing can not
grow in the submerge fishes, fruits and other substances
...
In research it
is found, that formalin forms a compound within cell of the fishes
...
It enters within human body with the cooked
food
...
Insecticides are used in the storage food and vegetables
...
Infants are more affected
...
So infants suffer
from various types of illness and their mental development is retarded
...
Antibiotic
Used in fish and cattle food, Only approved drugs can be
used
...
2
...
products of tannery, coal, soil,
faeces of animals
...
Commercial colours
Unapproved colors used in Avoid to use inedible
industries,
used
in components, such as : waste
manufacturing
ice-cream, products of tannery, coal, soil,
blended ice-cream, sherbet, faeces of animals
...
4
...
dead body in the morgue etc
...
5
...
vegetables
Unapproved use of D
...
T in marketable, not to use D
...
T in
dry fish
...
6
...
Not to use carbide
...
Use of excess sorbet
...
7
...
and preparation of microbes
can mix with the food
...
To keep it alive and function
able, it requires food in time
...
Body cells are unable to absorb these directly
...
Digestive system: There is a particular system for the digestion of food that is called
digestive system
...
The
digestive system consists of alimentary canal and the digestive glands
...
In two ways the food substances turn absorptionable
...
(1) Mechanical process: Teeth help in chewing or masticating the food substances
...
Within stomach and intestine these
particles turn into pulp
...
Enzyme in the
digestive secretion helps to enhance chemical reaction
...
Besides, intra cellular reaction also depends on enzymes
...
Parts of this canal may be narrow
...
It is a transverse opening below
the nostrils and bounded by lips
...
These organs help in digestion
directly or indirectly
...
The functions of tongue
are to move food around the mouth for mastigation
and to taste
...
These glands are located below the ear, at side
of the jaws and below the tongue
...
The secretion containing the enzymes named
ptyalin and moltes takes part in digestion
...
6 Digestive system of man
Tooth: Teeth are the hardest part of the body
...
Milk teeth appear first in childhood and are replaced by the
permanent teeth up to the age of 18 years
...
Such as :(a) Incisor : Incisors are used in cutting and
biting food
...
(c) Premolar : These teeth are specialized for
crushing and grinding
...
There are two teeth at the extreme end of
the jaw which are called molar
...
Structure of a teeth: The tooth typically consists of three parts
...
Biology
73
(2) Root: The part inner part below the gum
...
Each tooth, composed of these components, are –
(a) Dentine: The main part of the tooth consists
of hard substances
...
Enamel is the hardest component of a tooth
...
(c) Pulp: Dentine surrounds a pulp cavity with
blood vessels (artery and vein), soft cells and
nerves running through it
...
8 Longitudinal section of teeth
nourishes dentine with food molecules and
oxygen
...
Tooth
remains attached with the gums by means of this cement
...
Food passes to oesophagus
through the pharynx
...
Food passes to the stomach through oesophagus
...
Its wall is thick and muscular
...
Continuous contraction and relaxation of the muscular wall of
the stomach turn food material, bolus or pulps into semi fluid mass or chime
...
Intestine: The coiled duct, extended from behind the stomach, is the intestine
...
As :(a) Small intestine: The coiled, long duct which extends from the stomach up to the
large intestine, is divided into three parts
...
Bile duct
from gall bladder, pancreatic duct of pancreas joins just before it, opens into the
duodenum
...
The inner wall of the intestine bears finger like
projections called villi
...
Villi absorb the vast majority of small soluble food molecules produced by digestion
...
It is the wider part of the alimentary canal
...
As
caecum, color, rectum
...
This is appendix
...
It forms and deposits undigested part of food that is bowel
...
This aperture is anus
...
The digestive glands in human are as follows :
(a) Salivary glands : A pair of parotid glands, located in front and below each ear,
below the jaw sub maxillary and below the tongue opens into the buccal cavity through
different ducts
...
Salivary juice
contains water and ptyalin
...
It
is the largest gland of the body and is deep brown in colour
...
Basically liver consists of four incomplete lobes
...
Each lobule contains numerous cells
...
Bile
is alkaline in nature
...
So it is also called the
organic laboratory
...
It stores bile
...
Gall bladder is connected with bile duct, pancreas are
connected with the help of pancreatic duct
...
It enters to the duodenum through pancreaticduct
...
Functions of liver: The liver produces bile
...
It is stored in gall bladder
...
There is no
enzyme in the bile
...
Bile neutralizes the
acidic chime and creates alkaline medium
...
So foods are
not digested in acidic medium
...
So it
makes easier for lipase to digest fats easily
...
After various chemical reactions urea, uric acid, ammonia, nitrogen products are
produced and help in absorption of fats
...
Thus the level of blood glucose remains under control
...
Pancreas secretes digestive juice, on the other hand it secretes hormones that
Biology
75
control the level of glucose
...
Pancreatic juice passes into the duodenum through pancreatic duct which joins the
common bile duct (hepato pancreatic duct)
...
It contains amylase, lipase, trypsin named enzymes
...
It maintains acid-base
balance, water balance and controls body temperature
...
Gastric glands: The glands in the stomach wall are called gastric glands
...
Intestinal glands: Intestinal wall possesses villi contains intestinal glands
...
Digestion of food: The bio-chemical process, by which larger complex, insoluble,
unobservable food substances take part in organic chemical reactions and simple soluble,
absorbable transform into form in presence of particular enzyme and hormones, is called
digestion
...
At last blood transports
digested simple ingredients to different parts of the body
...
Saliva from the salivary glands
mixes with the food
...
Saliva contains
the salivary enzymes ptyalin or salivary amylase
...
Protein and fats have no change in the buccal cavity
...
Muscular wall of the
alimentary canal contracts and relaxes simultaneously
...
and no digestion of food occurs in the oesophagus
...
Converts inactive pepsinogen into active pepsin, makes a acidic medium to
perform its proper function
...
The compound is
composed of two or more amino acid that is known as peptide
...
Because gastric juice do not contain any particular
enzyme for the digestion of carbohydrates and fats
...
The muscles of the
stomach contract and relax continuously
...
This is chime
...
Digestion in the small intestine: When the chime enters the duodenum, two secretions
namely pancreatic juice from the pancreas and bile from the liver poured through the
bile duct
...
Pancreatic juice
neutralizes the acidity of chime
...
Bile is secreted from the liver
...
Bile salt
emulsifies fats that means it helps fat
droplets to mix with water
...
9 Absorption of soluble food and fats in ilium
one of the constituents of bile
...
Lipase converts
the fat droplets into fatty acid and glycerol
...
Intestinal juice
contains the enzymes, maltase, lactose, surcease etc
...
Amylase enzyme converts the maltase into
glucose
...
The inner
surface of the intestine (ileum) is covered by finger-like projections called villi, which
contains capillary net work
...
The lacteal is surrounded by flood
capillaries
...
So it increases the surface area of the ileum
...
These blood vessels (capillaries) join together to from a large blood vessel called the
hepatic portal vein which carries blood to the liver
...
At first it is carried by lymph then mixes with the blood stream
...
At the time of
flowing blood, a kind of substance comes out of the capillaries
...
Lymph supplies nutrients to the cell and collects the waste products and returns
to the blood stream
...
Digestion in large intestine: No chemical reaction or digestion takes place in the large
intestine
...
Besides
there remain a small portion of protein, lipid, salt and excess enzymes
...
Then the indigested
products concentrate here and turn into faeces or stool
...
According to need the faeces pass out through anus
...
It is an anabolic process
...
Such as : amino acid, glucose, fatty acid and glycerol
...
The digested food substances
are converted into protein, carbohydrates and lipid due to the action of enzymes secreted
from protoplasm
...
Sometimes intestinal disorder causes the under mentioned diseases or physical problems
...
There are many causes of indigestion or
disturbance in digestion
...
Pain in the upper abdomen,
abdominal flatulence, feeling stomach full, burning sensation in the chest, nausea or
vomiting, chest pain, sour belch etc are the symptoms of dyspepsia
...
To prevent dyspepsia, what we have to do – To avoid overeating chew food slowly in
the best way, avoid smoking
...
Dysentery : Dysentery is caused by infection of a protozoa named Entamoeba hisolytica
or by a bacteria named segela
...
The things we have to do is to prevent dysentery are as follows – drinking pure water,
wash fruits and vegetables carefully
...
Use sanitary latrine, wash hands and utensils carefully, follow treatment
prescribed by physician
...
Constipation: It is not a particular disease
...
There are various causes
of constipation, such as : habit of not responding when the bowel impulse sound its
alarm, excessive water absorption from the undigested part of food in the colour, slow
movement of the undigested part of the food in the alimentary canal, leading a lazy life,
intestinal disorder, slows down the contraction of colonic muscles, not taking roughage
containing food increase the probability constipation
...
That results in uneasy feeling
in the abdomen, abdominal pain and various accompanying disorder
...
Make a habit of regular walking and passing out of stool
...
Long
irregularities, in taking food, cause the over secretion of acid
...
Feeling continuous dull pain in the mid part of the abdomen is caused by this disease
...
It may
cause vomiting
...
The disease can be
ascertained by endoscope or barium x-rays
...
Take food regularly, avoid stimulating substances, as – coffee,
cigarette etc
...
Appendicitis : In the right side of the lower part of the abdomen where a finger like pouch joins
with the caecum of the large intestion is appendix
...
Pain starts around the navel, after sometime that moves downward in the right
side
...
In this
situation consult the doctor, transfer patient with the advice of a doctor
...
If the infection of appendix is severe, it can
burst and may be fatal that may lead to even death
...
Human body is the host of
many worms
...
Abdominal pain, weakness, indigestion, feeling of uneasiness in the abdomen,
nausea, insomnia, loss of appetite, pale face, anemia, swelling of hand and legs,
enlarged abdomen, symptoms are the causes of worms
...
Through pathological examination
of stool it can be ascertained in the abdomen
...
Food substances become impure by flies and worm affected people
...
The preventive measures are as follows – making habit of taking raw
fruits by proper washing, before taking food wash your hands properly, use sanitary
latrine, not to walk bear footed, not to take semi-boiled food
...
Generally infants suffer from Diarrhoea
...
So water reduces, the patient becomes weak
...
At
that time if the proper treatment is not ensured, then the patient may even die
...
In this situation the
patient refuses to take any foods and drinks
...
There is every possibility to spread this disease, such as : drinking impure water, taking
of other and dirty foods use of unclean utensils, in take of food with dirty hands
...
Now adays, oral saline, prepared by Institute of Diarrhea Research Centre, is
available in the market
...
It
is to be prepared following the instruction
...
You have learned here to prepare oral saline
...
Rice saline is prepared by mixing 50 gm of rice powder, one pinch of salt
with 1 litre of water
...
After recovery the patient should be supplied excessive food at least a week
...
82% of death due to rota virus occurs
in deprived poor countries
...
The percentage of death is high in
poor countries
...
Work : Prepare oral saline in a group
...
80
Biology
Exercise
Short answer question
1
...
How many essential mineral nutrients do plants use?
3
...
What is the reason of Anemia?
5
...
Describe the structure of a tooth with diagram
...
What are the characteristics of balanced diet?
Multiple choice question
1
...
Zinc
b
...
Boron
d
...
Chlorosis is caused by…
i
...
sulfur deficiency
iii
...
i & ii
b
...
ii & iii
d
...
Five year old Sanjana can see all the writings in the book
...
3
...
To prevent from this disease which vitamin Sanjana has to take?
i) liver
ii) carrot
iii) Mola fish
Which one is correct?
a) i and ii
b) i and iii
c) ii and iii
d) i, ii and iii
Biology
81
Creative question:
1
...
Raihan spends most of the time in the laboratory
...
On the other hand his younger brother Jahir is the regular player of
national team
...
a) What type of food is the source of nitrogen?
b) What do you mean by high protein, explain it?
c) Which food should be in much quantity in Jahir’s food chart? Explain its cause
...
Raihan that is included in Jahir’s
food chart? Analysis this opinion
2
...
To
solve the problems, he asks for help from a horticulturist, and the horticulturist
suggests Irfan Ali to apply some essential nutrient elements in his garden
...
What is a micronutrient?
b
...
c
...
d
...
82
Biology
Chapter Six
Transport in organisms
Transport is a very essential system functioning all the time in all the living organisms
...
Translocation of water and minerals absorbed form soil and taken to the leaves is
as essential as the translocation of food produced in the leaves to the different parts of
the plant body
...
Transport systems in plants and human bodies are discussed in
this chapter
...
x Explain the plant and water relationship
...
x Explain the translocation of substances
produced
through
the
process
photosynthesis
...
x Explain the concept and significance of the
process transpiration
...
x Evaluate that transpiration is a very essential evil
...
x Explain the concept of transportation in
human body
x Explain the components of blood
...
x Be able to choose blood depending upon the
blood group characteristics
...
x Analyse the adaptation of heart’s structure
and its activity
...
x Explain the ideal blood pressure
...
x Analyse the role of cholesterol in blood circulation
...
x Analyse the symptoms, causes, remedy and
prevention of diseases relating to heart
...
x Measure the pulse rate and blood pressure at
the time of taking rest and after exercise and
can compare between them in two situations
...
x One could be aware of keeping heart healthy and
create awareness to prevent heart diseases and
Biology
83
Plant and water relationship
Another name of water is life
...
We know that
protoplasm is the physical basis of life
...
This is why
water is called the fluid of life
...
Moreover, all the metabolic reactions that usually occur in a plant will be
ceased in deficiency of water
...
There is no substitute for water in maintaining the living nature of protoplasm
...
It is necessary to ascertain the supply of water in necessary amount for keeping the
process transpiration and photosynthesis on their running state
...
3
...
The significance of water in many metabolic reactions
is immense
...
Water plays the important roles in the cellular growth of plant and in their
movement
...
Plants mainly absorb water at their roots from the soil
...
1) Imbibition: If a piece of dry wood is placed in water, it will absorb some water in it
...
This is why the piece of
wood has absorbed the water
...
The substances such as
cellulose, starch, gelatin etc
...
When they come in contact with water,
they absorb it, and conversely, they become constricted when they face deficiency of the
liquid
...
It is a unique process for absorbing water
...
Essentials: a small bowl, attar or any incense
...
2) Diffusion: If some incense is poured in a corner of a room, its fragrance is
immediately spread throughout the whole room
...
If some sugar is added to the water of a glass, instantly the water of the
glass tastes sweet
...
It is a physical process
...
At a constant
temperature and atmospheric pressure, the potential energy of a substance to diffuse
from a solution of its higher concentration to a solution of its lower concentration is
called its diffusion pressure
...
Because of the diffusion pressure deficit in the mesophyll tissue of a
leaf, a cell in deficiency of water absorbs it from its adjacent cell
...
3) Osmosis: Do you know what osmosis is? Have you ever observed when a mother
places some dried grapes in water, the constricted raisins are immediately swelled up
being turgid
...
Could you think how
this has happened? This is a very essential phenomenon
...
This process can be watched accomplishing in the
laboratory without the involvement of any living cell
...
When
two solutions of different concentration having the same solute and solvent are separated
with a selectively permeable membrane, the solvent flows from its higher concentration
to its lower concentration
...
Work: Experiment on demonstrating osmosis through cell to cell
...
Prepare a potato osmoscope, and by pouring down the sugar beverage, prove the
process osmosis
...
For
the convenience of our discussion, we will know the facts about water absorption first
...
The diffusion pressure deficit in a cell of a leaf is developed because of
transpiration, and then water from the adjacent cell moves towards the cell
...
This way a continuous diffusion pressure deficit is extended up to
root hair and a suction force is developed
...
Water enters into the root hair cell through the
process of osmosis and diffusion
...
This way of movement of water is called cell-to-cell
osmosis
...
Water having once entered into the vascular bundles, it
Biology
85
continues to be taken up and flowed laterally through xylem tissue
...
Figure: 6
...
Though some salts are absorbed through root hair, mainly the
meristematic region of the tip of root functions as the main region of absorbing mineral
salts
...
Absorption of salts is done mainly
by the two ways and they are passive absorption and active absorption
...
2) Active absorption: Active absorption is the absorption of ions with the help of
metabolic energy produced in the cells
...
We know that water and mineral salts are taken up the stem in plants through the vessels
of xylem tissue
...
In this way water
reaches leaves, food is produced there
...
The
food is translocated through the sieve tubes of phloem tissue
...
The compounds in the lower region flow downwards and compound
synthesized in the upper region flow upwards and the substances synthesized in the
middle region flow both the directions upwards and downwards
...
Movement or transportation of water and mineral salts in plants called
86
Biology
translocation in plants
...
Now, the matter of consideration is that the
water and mineral substances, that are to be used, must be taken up to the place where
the reactions will occur
...
Water and mineral salts being absorbed through the root hair reach the vessels
of the xylem tissue crossing the cortex region and gradually reach the leaves along with
the current or flow of transpiration
...
The food
produced in the leaf reaches the different regions of a plant through sieve tubes of
phloem tissue
...
This is why it can be said that translocation in plants
is a very important activity for the existence of their life
...
Plants absorb water from the soil with the process osmosis
...
Side by side plants also absorb mineral
nutrients from the soil though the process of absorbing water and the process of
absorbing mineral salts are much different
...
Water and mineral salts dissolved in it
are collectively known as cell sap
...
Ascent of sap: Roots absorbs water and mineral salts
...
Concurrently, the lateral translocation of
cell sap also occurs
...
At the first stage, osmosis, diffusion
and suction from transpiration etc
...
The water and the mineral substances absorbed
by root hair move to the adjacent cell by the process of osmosis
...
Moving in this way, water and mineral substances that once
reach the vascular bundle of the root, ultimately, reach the
mesophyll tissue of leaves through the vascular bundle of
the stem
...
Essentials: Peporomia plant, bottle of glass, water and
safranin
...
Place a living Peporomia plant in the bottle in such a way that its roots are submerged
Biology
87
into water
...
Translocation of the substances produced in photosynthesis: You have learnt earlier
that plants absorb water by the process osmosis
...
These very leaves utilize water for the process
photosynthesis
...
The food produced in that way is conducted to the
different parts of a plant
...
After the completion of
deriving energy through respiration, the remaining food is stored in some special regions
of a plant
...
Now, we will study how the food produced in
photosynthesis is conducted to the different regions of a plant body
...
This is done by sieve tubes of phloem
...
We knwo that there are xylem bundles and phloem bundles in a
vascular bundle
...
Sieve tube is a kind of thin walled living cell without
nucleus
...
The septa in
between them being disappeared in some places develop sieve shaped forms
...
In winter, these openings are
blocked because of the deposition of chemical substance callose, and thus the movement
of food is inhibited
...
Transpiration: Life cannot be imagined without water
...
They use a very little part of the absorbed water for their metabolic
activities
...
The
physiological process by which generally the land plants through their aerial part lose
water in the form of water vapour is called transpiration
...
1) Stomatal transpiration: There are special types of openings with two guard cells in
the leaves, young stems and sepals and petals of flowers
...
90-95% of the total transpiration in a plant occurs through the stomata
...
This layer is called cuticle
...
The process is called
cuticular transpiration
...
The cells aggregated around a lenticel are loosely fitted and
water from inside can be lost through it
...
Through transpiration, as excess water is escaped being evaporated, a suction force
being developed causes the root to absorb water
...
They are roughly grouped into two: a) external factors and b) internal factors
...
Water can easily be vapourized at high temperature and thus the process transpiration is
accelerated
...
As a result, transpiration proceeds speedily
...
2) Relative humidity: The proportionate ratio of the amount of water vapour in the air
of the atmosphere and the amount of water vapour that the air can hold at a given
temperature is its relative humidity
...
Conversely, in spite of the presence of low amount of water vapour in atmosphere, the
atmosphere may be humid for the low water vapour holding capacity of the air
...
If
the relative humidity is high, the air being saturated loses its water vapour holding
capacity
...
3) Light: In presence of light, stomata get opened, and so the rate of transpiration
increases
...
With the
fluctuation of light, the openings of the stomata also change
...
Biology
89
4) Wind velocity: Because of transpiration, air around the plant gets moist, and causes
the rate of transpiration slow
...
With the wind, the leaves are swung and a kind of pressure is
exerted on stomata and, so water vapour at a high rate comes out through them
...
If the
atmospheric pressure raises, evaporation declines and so the rate of transpiration also
decreases
...
b) Internal factors
1) Stomata: The rate of transpiration varies with the number, volume, structure and
arrangement of stomata
...
3) Volume of mesophyll: If the volume of leaf is high, the rate of transpiration will also be
high
...
4) Volume of the aerial parts of the plant: If the total volume with all the aerial parts
of a plant is increased, the rate of transpiration will be high
...
change the rate of
transpiration
...
Essentials: A fresh potted plant to be required for the experiment, a glass bell jar or a
big and narrow cellophane bag, thread or clip and required water
...
Now, a branch of the plant with
some leaves having been covered with a cellophane
bag will be clipped or tied with thread or will be
covered with a bell jar
...
The pot in this stage will be kept for an hour
...
4 Test of
Observation: After an hour, it will be found that water drops are studded on the inner
surface of the cellophane bag and the whole bag would become fuzzy
...
So, it has been proved that a plant
releases water in vapour form through its aerial parts
...
2) The opening of the cellophane bag should be tightly tied so that no air can get in or
come out
...
The
metabolic activities of any living cell are mostly dependent on this process
...
With the suction force, a plant absorbs water and mineral salts
through its root hairs and the absorbed water and mineral salts are conducted to the
leaves
...
In the mesophyll
of leaf, diffusion pressure deficit is developed because of transpiration and helps the
absorption of water
...
On the contrary, though this important process transpiration contributes many useful acts
to a plant, it also plays some harmful roles in it
...
As a result, the plant may die
...
To face
this crisis, nature causes many plants to drop leaves in winter
...
So, it can be said that transpiration is an essential activity for a plant though it causes
some harms to it
...
Transportation in human body
Blood is the source of vitality
...
So the
cells remain active and alive
...
The
distribution of nutrients and oxygen throughout the
Biology
91
body and the removal of body wastes is performed by this system
...
This type of
circulatory system is called closed circulatory system
...
The advantages of this
circulatory system are (1) Blood reaches to different organs directly, (2) can control the
flow of blood to a particular organ by changing its diameter and the distribution can be
adjusted depending on demand, (3) blood goes round the whole body and returns to the
heart fast
...
There are two types of circulatory systems
...
It
consists of heart, arteries, veins and capillaries
...
It consists of
lymph, lymphatic ducts lacteal
...
A red coloured fluid
spreads out from the place of slaughtering
...
It is a viscous fluid
...
Due to the
presence of hemoglobin blood appears red
...
Blood originates from the bone marrow
...
x Plasma : The colourless fluid part of plasma which constitutes about 55% volume of
whole blood
...
Small amount portion, organic
subs and small portion of inorganic salts are dissolved in it
...
Besides it contains small amount of sodium chloride,
sodium bi –carbonate and amino acid
...
The cells absorb the nutrients, repair the worn out tissues and help in growth
...
(a) Red blood corpuscles or erythrocytes: Among the three blood cells the red blood
corpuscles are huge in number and plays an important role for the transportation of
oxygen required for respiration
...
There are approximately 5 billion of red blood
corpuscle present in cubic milliliter of an adult male
...
The amount of red blood corpuscles in infants is comparatively high
...
Haemoglobin of red blood corpuscles transports oxygen as oxyheamoglobin and also
carbon dioxide
...
It appears red because of
its presence
...
In Bangladesh almost two third of population suffers
from this disease
...
(b) White blood corpuscles : There are some kinds of white blood corpuscles in human
blood
...
There are 510 thousand white blood corpuscles in cubic milliliter
...
It is colourless but contains a nucleus
...
White blood corpuscle engulfs the germs by spreading pseudopodia
...
The dead white blood corpuscles turn into pus
...
White blood corpuscles acts
as a guard, destroys the germ by the process of phagocytosis and produces antibody
...
They remain in cluster
...
5 million platelets per cubic milliliter of blood
...
It originates in the bone marrow
...
It helps
in blood clotting
...
This may lead the patient to a life threatening situation
...
Difference between Red blood corpuscles and White blood corpuscles
Characteristics
Red Blood Corpuscles
White Blood Corpuscles
Nucleus
Shape
Haemoglobine
Number
Functions
Biology
93
Functions of blood : Blood is an important ingredients
...
Such as –
1) Oxygen transport : Red blood corpuscles transports oxygen as oxyhaemoglobin to the cells
...
Carbon di-oxide is transported in the form of sodium bi-carbonate
dissolved in the plasma
...
3) Transportation of digested food: It provides plasma, glucose, aminoacid, fat
granules in the cell
...
5) Elimination of waste products: Blood carries all the waste products and eliminates
these as urea, uric acid and carbon di-oxide
...
It mixes with the blood directly and is circulated to the different organs
of the body according to its need
...
7) Prevention of Diseases: Some types of white blood cells attack and engulf germs by
the process of phagocytes, thus prevents the body from the attack of germs
...
8) Blood clotting: If there is wound at any part of the body the clotting of blood heals
the wound, preventing excess loss of blood
...
His or her blood
group is B
...
Blood
can be classified into different groups depending upon the presence of these antigens and
antibodies
...
Scientist karl Landsteiner in 1701 for the first
time classified and named human blood and placed it into A, B, AB and O four groups
...
Types antigens and antibodies in different blood group is shown in the table belowBlood group
Antigen (in red blood
Antibodies (in plasma)
corpuscles or cells)
A
A
b
B
B
a
AB
A,B
No antibodies
O
Neither
a, b
94
Biology
We have observed the presence of different antigens and antibodies with in the blood
...
Example –
1
...
2
...
3
...
4
...
Table : On the basis of the blood group the donor’s and recipient’s list
...
A
A, AB
A and O
B
B, AB
B and O
AB
AB
All group
O
A, B, AB, O
O
From this table you can see that people with O are called universal donor
...
So the people with blood group
AB are called universal recipients
...
Emergency transfusion of blood is the only way to recover this
anemia
...
Emergency can be met
by blood transfusion from one to another person directly or by using collected blood
from blood bank to cause to enter blood from others through the veins is named blood
transfusion
...
Without
examining the blood group and its nature, blood should not be transfused at any
circumstances
...
Example agglutination red blood corpuscles, decomposition,
causes jaundice and elimination of red blood corpuscles (haemoglobin) with urine
...
Blood has no
substitute, in this situation a lot of blood is necessary
...
To meet up this emergency situation the cooperation of
general mass is necessary
...
It causes no harm to the
donor
...
20 million of red blood
corpuscles are produced in every second
...
This amount of blood loss will not create any harm to donor
...
Example blood
donation on a particular day or occasion
...
Now people are more conscious and eager to donate
blood or accept blood to meet the crisis
...
It is situated in the left side in between the two lungs
...
It surrounded by a thin membrane named pericardium
...
(1) Epicardium: Basically it consists of connective tissue
...
Fat bodies remain scattered on it
...
It consists of
strong involuntary muscles
...
The chambers of the heart are surrounded by
this the endocardium
...
The inner part of the heart is
hollow and four chambered
...
The atria are comparatively thin
walled and venticles wall are muscular and
thick
...
The aperture between the two atria (atrium singular) and ventricle are guarded by valves
...
Similarly left atrium and ventricle
is guarded by a bicuspid value made up
of two flaps
...
Circulation of blood through the
heart: We have learned earlier that heart
acts like a pump
...
The
continuous contraction and relaxation
transports blood throughout the whole
96
Biology
body
...
A complete contraction (systole) and relaxation (diastole) of the heart
constitutes a heart beat
...
Such as – deoxygenate blood from the superior vena cava enters right
atrium
...
The walls of the two atrium contract and then muscles of the ventricle relax
...
So the deoxygenated blood from the right (auricle) enters into the right ventricle at the
same time left Sino auricular ventricular aperture guarded by bicuspid valve opens
...
So blood of the ventricle cannot return to the atrium when the two ventricles
relax deoxygenated blood, the right ventricle passes through the pulmonary artery
towards the lungs
...
At the same time oxygenated blood leaves the left ventricle through the aorta towards the
body and the opening of both the artery (aorta and pulmonary artery) are closed by semi
lunar valves which prevents blood returning into the ventricle
...
Functions of Heart: Heart is the principal organ of the circulatory system
...
The human heart is divided into four chambers
...
Blood vessels : The channels, through which mass flow of the blood occurs, are called
blood vessels
...
According to the size, shape and function blood vessels are of three types; artery,
veins and capillary1
...
Pulmonary artery is the exception
...
Each artery is made of three layers : (1) Tunica external- which is made of connective
tissues
...
(3)
Tunica intimae is the innermost layer made of simple endothelial tissue
...
The arteries do not have any values and has narrow
passage or lumen
...
The dilation and contraction of artery are
known as pulse
...
The ripple of pressure
which passes down the artery
...
You can
feel the pulse by pressing the finger tips of one hand on the wrist of the other
...
These connect with smallest artery in one side and vein on
the other side
...
Each cell is surrounded by blood capillaries
...
Through this thin layer substances dissolved into the blood diffuse into the
cells
...
They spread all over the body just like artery veins originate
from the capillaries, numerous capillaries together form small veniule, veins and vena
cave open directly into the heart
...
The veins have valves and wider passage or
lumen
...
Work : Determine differences between artery and vein
...
origin and ending
2
...
Nature of blood
4
...
Lumen or passage
6
...
Location
8 Blood pressure
Vein
Blood pressure: Blood pressure is the pressure of the blood against the wall of the
arteries
...
The pressure in the artery during
systolic condition is called systolic blood pressure
...
Relaxation of the heart is called diastole
...
The pressure in the artery during
diastole condition is called the diastolic condition when blood pressure is less
...
By observing systolic
and diastolic pressure with the help of this machine blood pressure is determined
...
Ideal blood pressure: According to the physician a normal adult man’s blood pressure
is generally near about 120/80
...
That indicates two ranges one
for higher and the next one for lower
...
The blood
pressure in the arteries decreases during diastole
...
In between the time of two heart beats this pressure is
created
...
The normal rate of the pulse, therefore the heart beat rate is about 70 beat per
minute in an adult at rest
...
It can be measured by the blood pressure machine on sphygmomanometer
...
According to World Health Organization report within 2020 stroke,
coronary artery diseases will the number one life threatening disease
...
One of the main causes of heart
disease and stroke is high blood pressure
...
When blood pressure rises above the normal
pressure then it is considered as high blood pressure
...
When systolic and diastolic pressures rise more than the normal pressure, this
is called high blood pressure or hypertension
...
Besides this those, who suffer from tension or smoking habit, have the probability of
hypertension
...
Eclamsia at
the time of child birth is the cause of hypertension
...
Before measuring blood pressure the patient
Biology
99
should take rest
...
Symptoms and signs of Hypertension: Headache, primary symptom is ache at the back
of the head, vertigo, shoulder pain, palpitation, and weakness
...
Work : Prevention : of measuring bloodtaking inand write yourand vegetables, Regular
Learn the skill Making habit of pressure fresh fruits friends blood pressure in
the table or physical
exercise given below
...
smoking
...
If the pressure is very high, consult a doctor and take medicine regularly
...
It is an important component in the
cells of higher animal
...
It is made of
three types of lipoprotein
...
Generally there is 70% LDL in our blood
...
Usually HDL (high density lipoprotein) is called good
protein
...
HDL does the quiet opposite task of LDL in growth
...
It remains within our food and as fat in our body
...
Blood fat exists as a compound which is formed by the
combination of triglyceride and cholesterol
...
Range of cholesterol in blood that is shown in the table below
...
Female m mol/L
LDL
1
...
53
1
...
53
HDL
0
...
45
0
...
68
Triglyceride
0
...
81
0
...
53
Food contains huge amount of cholesterol
...
Problems of high cholesterol in blood : Different health problems are created for the
presence of high cholesterol
...
It increases the possibility of
100
Biology
having coronary heart disease
...
So cardiac muscles can not get sufficient oxygen that causes
damage to the muscles
...
This is called angina
...
In this situation brain cells tend to die
...
Functions of cholesterol- Usefulness and its risk:
Cholesterol is involved in constructing cell membrane and its protection
...
It helps in producing and
reproducing hormones such as, androgen and estrogen
...
Cholesterol in skin
prepares vitamin ‘D’ in presence of sunlight
...
For the activities neurons
cholesterol is essential
...
It is
proved by research the presence of high cholesterol is related to the irregularities of heart
and blood transportation
...
Increased amount of cholesterol deposits
in the gall bladder as sediments
...
If the amount of lipid increases up to the 2030 percent for certain reasons diseases like malaria, diabetes, syphilis etc and poisonous
action of alcohol, carbon monoxide, phosphorus etc are the causes of increasing
cholesterol
...
Irregularities in blood- (Leukemia) :
There are three types of blood corpuscles in a healthy body
...
Germs enter the blood, white blood
corpuscles destroy them easily
...
Blood cells are made by the red bone marrow of certain bones
...
It is formed because of over formation and
over multiplication of white blood cells from the bone marrow
...
These
are several varieties of leukemia
...
Some diseases of blood circulatory system and remedy:
Heart Attack: When blood clots at any parts of the heart that stops the blood circulation
or is obstructed
...
It results in
myocardium infraction or coronary thrombosis disease
...
Oxygen and
digested food products are carried by the blood stream to all cells of the body from heart
...
These are called coronary artery
...
So it causes life threatening heart disease
...
The main causes of this disease are over weight, taking of unhealthy diet, example:- oil
enriched food (Biriani, Tehari etc
...
(Berger, Beef or chicken patties etc
...
After all depression,
emotional strain, anxiety, sadness increase the risk of this disease of any age
...
The pain spreads
from the left side to all over chest
...
The
patient complains that he or she feels pressure on the chest and sweats
...
C
...
- To keep free from this disease some rules should be followed, so that the blood
pressure can be controlled
...
- Change food habit, eating sufficient amount of fruits and vegetables
...
Measures to keep the heart sound / healthy: Through rhythmic contraction and
relaxation, the cardiac muscles control the circulation of blood within the body from a
particular stage of the embryonic condition till the last moment of death
...
exact life style and selection of food is the
necessary to keep the heart healthy
...
For alcoholism and addiction increase heart beat than its normal amount
...
Poisoning due to smoking and nicotine of tobacco (Jordha) damages not only the other
organs but also the heart
...
Avoiding fatty diet, Such as- oils, fats, excess carbohydrate and taking balanced diet,
regular exercise and walking can make a person healthy
...
The initial
attack of the disease usually occurs in childhood and may affect many parts of the body
especially the heart
...
So heart can not pump adequate blood and flow of blood
within the body decreases
...
Later increasing
severity of disease, weight loss, anemia, exhaustion, poor appetite, pallor etc indicate the
presence of the disease
...
If the disease is detected or identified in early stage, penicillin may be used to
prevent it
...
Exercise
Short answer questions
1
...
What is diffusion?
3
...
What are the functions of artery?
5
...
Describe the measures of keeping the heart healthy / sound
...
Describe the process of absorbing water with diagram
...
What is the name of the heart covering membrane?
a) Epicardium
b) Miocardium
c) Pericardium
d) Endocardium
2
...
In this case, what is the cause of the swelling of these raisins?
a
...
absorption
c
...
imbibition
Observe the stem given below and answer questions 3 and 4
...
If blood input is necessary for Rafin , from whom he can take blood?
a) Tamim b) Tasmia
c) Ratul
d) Tamim and Ratul
4
...
Which one is correct?
a) i and ii b) i and iii
c) ii and iii
d) i, ii and iii
Creative question
1
...
b
...
d
...
Analyze the problems that may develop with the plant if the element X does not
reach the region Y
...
Mr
...
He serves in a socio-economic institution
...
On the other hand his 7 years old daughter Moon
feels joint pain, and her skin turns swollen and reddish
...
After some tests he advised necessary measures
...
Hasan’s disease?
d) Which disease is incurable from the problems mentioned in stem- explain with
reasons
...
gaseous exchange in
plants are of different types
...
Sun
At the end of this chapter, we will be able tox Explain the idea of plant’s gaseous exchange
...
x Describe the structure and function of lungs
...
x Explain the causes, symptoms, remedy and the preventive measures of respiratory
system
...
x Draw the labelled diagram of lung
...
Biology
105
Gas exchange in plants
We know that photosynthesis and respiration
are the two very important processes in the
life of a plant
...
These two processes are
Respiration photosynthesis
accomplished through many chemical
(Plants and animals)
reactions
...
1
the environment
...
The exchange of oxygen and carbon dioxide and other gases occurs
through the stomata of leaves and lenticels on the bark of the mature stem
...
In daylight or in the presence of sufficient light, the rate of photosynthesis
becomes high
...
Reversibly, a part of carbon dioxide gas, produced in respiration, is used in
photosynthesis and so the amount of gases, exchanged, are approximately the same
...
But the
respiration process occurs round the clock day and night, and the production of CO2
continues
...
These
gases are also exchanged through the lenticels developed in the bark of the mature stem
...
A plant obtains its required gases from its environment
...
In
this way exchange of gases goes on in a plant
...
Not a single animal can
survive without oxygen even for a while
...
Within the somatic or
body cells food substance uses oxygen to break down the digested food substances sugar
(glucose) to produce heat and energy
...
Oxygen reacts with the digested food substances (sugar, glucose) to produce carbon dioxide and oxygen
...
Here oxygen is absorbed and
carbon dioxide is expelled
...
The biological process, in which
digested food substances in the body cell are oxidized, converts the potential energy into
useable (kinetic energy) energy and eliminates carbon dioxide, is called respiration
...
The simple equation of respiration is given below6CO2 + 6H2O + Energy (ATP)
C6H12O6 + 6O2
Glucose + oxygen
carbon di-oxide + water + energy (ATP)
You have learnt in class seven that inhaling of oxygen is inspiration and breathing out
of carbon dioxide is expiration
...
In both conscious and unconscious
conditions inhaling of oxygen and expelling of carbon dioxide goes on continuously
...
So animals survive
...
These organs
comprise the respiratory organs
...
The
organs related with the respiratory system are :
(1) Nasal cavity and Nasal passage,
(2) pharynx,
(3) larynx,
(4) trachea,
(5) bronchus,
(6) lung and
(7) diaphragm
...
It is a triangular
hollow organ situated above the buckle cavity
...
A
specific type of nerve stimulates the organ, so it gives
us the sense of smell
...
Nasal passage extends from aperture in front of the
nose and up to pharynx behind
...
Its front side is covered with cilia and
hinder part is lined by mucous producing membrane
...
2 Human respiratory system
Bronchus
Figure: 7
...
Before entering the lung this makes the air relatively free from dirt to some extent
...
So that the
cool air can not do any harm to the lung
...
It extends posteriorly of the nasal passage upto the upper part of larynx
...
It is situated below the pharynx and at
the top of the trachea
...
These cords are vocal cords
...
It acts as a lid at the time of taking food
...
So air gets into lungs through this passage
...
(4) Trachea- It is a long tube which lies in front of theoesophagus and extends from the
larynx downwards in the thoracic cavity
...
The inner layer of the trachea is covered with mucus membrane and cilia
...
But the constant rhythmic beating of the cilia the trapped dust,
germs and other unwanted particles throw it out
...
These are bronchi divides and sub divides
repeatedly form bronchioles
...
(6) Lungs- Lung is the main organ of the respiratory system
...
It is spongy, soft and light
reddish in colour
...
The enter surface
lungs
of the lung
...
Which is named
as pleura
...
It saves lungs from friction as the lungs rub
against the thorax during breathing
...
Lung contains numerous air
sacs or alveolus, smelled bronchioles and
Figure: 7
...
The air sacs are called the alveolus
...
So air can enter
from the nasal passage to the alveoli directly
...
The alveoli are surrounded by mesh work of
capillaries
...
The
wall of the alveoli and blood capillaries are so thin that gaseous exchange occurs
between them
...
It looks like a spreading or stretching umbrella
...
When
diaphragm expands it moves upward
...
Diaphragm plays an important role in respiration
...
Breathing- All the organs related to breathings remain open only through pharynx and
other ends of the organs remain closed
...
Nerve impulses
thorax
t
help in managing breathing
...
So the diaphragm goes
downwards and thoracic cavity expands
...
So
the pressure within the thoracic cavity
Figure: 7
...
So forcing the lung to expand and draw air through nose and trachea
...
After contraction the muscles relax
...
So the air
pressure increases, the lung shrinks back forcing to moisten and carbon dioxide enriches
air expel out again
...
In this way breathing goes on at every moment /
constantly
...
Gaseous exchange: means the exchange of oxygen and carbon dioxide
...
Gaseous exchange occurs in two
steps, such as absorption of oxygen and giving out or expelling of carbon dioxide
...
In blood
oxygen does not remain free
...
It is a temporary compound
...
During the blood transport a large amount of oxygen diffuses from the plasma to lymph
...
So the oxygen concentration in
plasma becomes less
...
In this way at first oxygen enters plasma and then into lymph or intracellular
fluid
...
The exchange of gases between alveoli and blood and tissue occurs by the process of
diffusion
...
After entering
oxygen into blood from the lung dissolving oxygen flows in two ways
...
From oxy
haemoglobin oxygen separates easily
...
At last from lymph
oxygen reaches to cell after penetrating the cell membrane
...
This carbon
dioxide at first diffuses through the cell membrane into the lymph and then from the lymph
enters the plasma by diffusing through blood capillaries
...
There after carbon
dioxide mainly transports in blood as bicarbonate to the lung
...
Then carbon dioxide forced out diffusing
through blood capillaries and alveoli
...
Apparatus : Two large test tubes, line water and two plastic tubes
...
Put the end of both
plastic tubes with in the test tubes that it touches the
water surface
...
Notice
Fig: 7
...
Notice is there any
difference in line water? It after 15 second there is no difference in the appearance of the
time water in the two tubes
...
Observation: You will observe that the lime water in the testtube B
...
Because exhaled air has entered into the lime water
...
Exhaled air contains more co2 than the inhaled air
...
So the colour of lime water remains unchanged
...
This
organ is damaged by the infection of bacteria virus owing to our ignorance and
uncarefulness causes complex diseases and infections
...
1
...
Asthma develops permanently due to prolong cough, cold and sneeze
...
Cause: Certain allergic foods, (prawn, beef, hilsha-fish etc
...
entering the lung with the inhaling air, can be the cause of Asthma
...
Exception: Difference from other disease is that a seasonal variation is noted
...
Symptoms and signs: The symptoms of the disease are as follows –
- Sudden increase in respiratory distress
...
- Rapid deep breathing is attempted and whizzing and whistling sound in the chest
...
- White cough secretion may come out with sputum cough
...
- During inspiration, the skin between two ribs is drawn inward
...
Remedy: By proper medication the disease is not fully cured
...
- Avoid of taking allergic food
...
To avoid eating or contact with items that exacerbate the symptoms of such asanimal fur, artificial fiber etc
...
- Stay away from smoking, tobacco, jarda, gul
...
Prevention :
- Live in the healthy / atmosphere
...
- Always carry breath relieving medicine and utilize it when necessary
...
Bronchitis: This is acute and chronic inflammation of the inner lining of any part of
the bronchi and bronchial tube is called bronchitis
...
Living in the unhealthy conditions, inhaling dust, polluted air, smoking
cigarettes and cold are some of the reasons that may cause bronchitis
...
Usually infants and elderly
persons are attacked by this disease
...
e
...
industrial dust, smoke
...
- At the time of coughing the patient feels severe chest pain
...
- Can not take solid food
...
Remedy : Preventive measures include- Stop smoking, drinking alcohol, use of tobacco
...
- Keep the patient in tolerable temperature and dry environment
...
g
...
- Taking full rest
...
- Abstain from dust, smoked
...
112
Biology
3
...
Excessive cold may cause disease
...
It is a dangerous disease for
children and elderly people
...
Symptoms: These include- Deposition of mucus like liquid substances which produce cough
...
- High fever and chest pain
...
Remedy: These include –
- Seeking timely advice from physician and to follow the treatment given
...
- Drink plenty of water
...
- Live in well ventilated house
...
4
...
Any body at
anytime may be affected by disease
...
Most of us think tuberculosis is only a lung
disease
...
Tuberculosis occurs at any organ of the body
...
Not every person infected with tuberculosis becomes very sick and the symptoms are not
exposed easily
...
Cause: The disease is caused by tubercle basillus, a type of bacterium
...
Diagnosis: This disease can be found out by skin test and ‘X’ ray
...
- Usually cough and cold continues more than three weeks
...
Evening sweat and rise of low fever
...
Biology
113
Remedy : It includes –
- Continue treatment according to the advice of physician
...
According to the physician’s instruction: Follow the rules strictly by to prevent from the
disease
...
- Keep the used material of the patient separately
...
- Proper treatment and nutritious adequate diet should be arranged without consulting
the physician medicine should not be stopped
...
C
...
The baby
should be vaccinated within one year after birth
...
At present there is an arrangement of vaccination in different health centres of the
country
...
Tumour and cancer: All of us are acquainted with the word tumour and cancer
...
In mitosis cell division a cell divides into
two and two cells divide into four cells and the process continues
...
If this control is lost due to any reason, cell division continues in an
irregular way
...
Formation of cancer cells is also the result of uncontrolled irregular cell division
...
Two genes E6 and E7 of the virus produce a chemical
substance that displaces the two protein molecules which control cell division
...
Sometimes these two genes amalgamate with those of host cell and stop the functions of
protein molecules that control increase of cell
...
Cancer is a dangerous disease
...
6
...
In our country it is the leading cause of male cancer death
...
114
-
Biology
Lung cancer may be caused by air and environmental pollution, habitat or can
polluted working place exposure to such substances (such as- asbestos, arsenic,
chromium, nickel, solid metal powder etc
...
- It is assumed that shortage of roughage in diet increases the possibility of the
disease
...
Primary
symptoms of lung cancer are found,
- Long tasting dry irritating cough
...
- Gradual or day by day loss of weight, loss of appetite
...
- Repeatedly infected by pneumonia and bronchitis
...
- Jaundice
...
- X-ray of chest
...
- After detection of the disease follow the advice of physician
...
Prevention : According to the view, preventive measures include- Abstaining from smoking and drinking alcohol
...
- Regular exercise
...
Professor Troll and other cancer experts of American Cancer Institute, University of
New York have disclosed that different vegetables can prevent cancer
...
What is cellular respiration?
2
...
What is Bronchitis?
4
...
What is the cause of Pneumonia?
Essay type question
1
...
Which is the cause of tuberculosis?
a) virus
b) bacteria
c) fungi
d) protozoa
2
...
Rita went to the doctor with a complaint of weakness
...
To meet this insufficiency he advised her
to take more nutritious food and vegetables
...
Which one is deficient in Rita’s blood?
a) Red blood corpuscles
b) white blood corpuscles
c) Platelet
d) plasma
...
Particular cell –
i) constitutes with iron
iii) contains carbon dioxide
Which one is correct?
a) i and ii
c) ii and iii
ii) reacts with oxygen
b) i and iii
d) i
...
Figure-P
Figure-Q
a) Which cell does carry oxygen in blood?
b) What do you mean by trachea?
c) Explain the process meant by ---- P
...
Give your opinion
...
Rashed and Jamil works in ship breaking in dusty
...
After different type of tests doctor diagnosed
that Rashed respiratory organ has irregular cell division
...
a) What is diaphragm?
b) What do you mean by external respiration?
c) Explain how does the disease spread in Rashed’s body
...
So all
the physiological phenomena are performed neatly
...
Some
products are produced by chemical reactions which are essential for body
...
For
example, the breakdown of glucose during respiration produces carbon dioxide
...
Elimination of nitrogenous waste
products and various diseases in kidney are discussed in this chapter
...
- Describe production of excretory products in human body
...
- Describe the structure and functions of nephron
...
- Describe the formation of kidney stones, remedy and prevention
...
- Explain the role of dialysis to maintain the normal functions of kidney
...
- Describe the diseases of urinary tract and measures taken to keep it free from diseases
...
- Drawa labled diagram of human kidney and nephron
...
- Draw leaflet to create awareness to keep kidney and urinary tract (ureter) free from diseases
...
These substances are of no use for the body, but it
may cause various diseases if they remain inside the
body for a long time
...
Excretory
system assists to remove the poisonous products from
the blood that maintains the physiological balance
...
Kidney is the excretory organ
...
Excretory products: Basically excretory product means nitrogenous waste
...
Almost 90% water is the
component of urine
...
The colour of the urine is light yellow due to the presence of a pigment called
urochrome
...
Kidney: Excretory organ of human body is kidney
...
They are red brown and
bean shaped
...
The chamber in the hilus
is pelvis
...
From the hilus the renal vein comes out
and renal artery enters the kidney
...
Each kidney is enclosed by one type of fibrous membrane
...
In
longitudinal section of each kidney shows two regions, the outer one is cortex and part is
inner medulla
...
Generally, there are 8-12 renal pyramids in the medulla
...
These papilla projects directly into the ureter
...
Each
uriniferous tubule has two parts, such as- nephron and collecting tubule
...
Biology
119
Nephron : The functional unit and secretory part of uriniferons tubule of kidney is
nephron
...
Each
nephron is composed of a renal corpuscle, malphigian body and renal tubule
...
Bowman’s capsule encloses the glomerulus
...
The bowman’s capsule, containing a small
cluster of blood vessels is called glomerules
...
These capillaries divide again and form a mass of fine capillaries
...
Glomerulus acts as a filter and produces glomerular filtrate from the blood
...
Each kidney contains about 2 millions renal tubules
...
g
...
Work: Draw a labelled diagram of kidney and a nephron
...
Urine contains nitrogenous
waste products, such as- urea, uric acid, ammonia, creatinine etc
...
Kidney has an important role to eliminate these harmful and needless
products
...
This urine reaches to the pelvis of the kidney through collecting tubules and
proceeds through the funnel like extended part of the pelvis and enters ureter
...
When the
urinary bladder is filled up with urine, a sensation of urination is created and allows
120
Biology
urine to pass out of the body through urethra
...
Kidney maintains the balance of mineral salts
e
...
Sodium chloride, potassium chloride etc
...
Work: Write down the organs that take part in expelling the waste produced in table
given below
...
Basically, most
of the water goes out of the body as urine
...
Nephron of kidney maintains the water equilibrium by re-absorption
...
If the blood contains too much water, blood
becomes dilute
...
Kidney stone: Small stones like substances produced by kidney is known as kidney
stone
...
But it has been noticed that the male
have the higher possibility of stone formation than the female
...
g
...
Initially formation of kidney stones causes no remarkable problem and problem occurs
when it goes downward the ureter water and obstructs urination
...
Blood passes into the urine
...
Treatment depends upon the size and location of the stones
...
Stones can be removed by
the modern methods uteros uteroscopic copic, ultra sonic lithtripsi or surgical operation
...
Complex
nephritis, excessive blood loss, diarrhoea etc are the causes of sudden kidney failure
...
Kidney machine (dialysis machine) can be used to remove the harmful waste
Biology
121
products from a patient’s blood
...
Dialysis: When kidney failure happens then the process of purifying by scientific
method is named dialysis
...
A kidney machine (dialysis machine) receives
blood through a tube connected to an artery
...
The ‘cleaned’ blood
is returned to the patient through a tube connected
to a vein
...
In this way a kidney machine
purifies blood through dialysis tubing
...
But regular
dialysis is expensive and time consuming
...
A person can survive
adequately with one kidney
...
But one should be aware / sure of tissue
matching between donor and recipient
...
Again the kidney transplant
can be done by collecting it from a dead man
...
Like
posthumous eye donation kidney donation can save the life of a kidney failure patient
...
Leading unhealthy living, drinking insufficient water causes urinary tract or ureter
disease
...
Consult with doctor as soon as immediately and with proper treatment most patients
recover completely
...
Measure to keep the urinary tract sound / free from diseases: Be careful about the
tonsillitis and scabies of the children, keep control of high blood pressure and diabetes
...
Work: Make a leaflet in a group regarding how to keep kidney and urinary tract sound
...
What is dialysis?
2
...
What is pelvis?
4
...
What do you mean by kidney stone?
Easy type question:
1
...
Multiple choices
...
Where urea is produced?
a) Kidney
c) body cell
b) liver
d) renal artery
...
Decreases the possibility of forming kidney stone?
i) decreasing body weight
ii) drinking insufficient water
iii) in taking less amount of protein
Which one is correct?
a) i and ii
c) ii and iii
b) i and iii
d) i, ii and iii
Read the stem and answer question 3 and 4
...
Recently
she excretes less urine and feels pain in the waist
...
Causes of producing less urinei) excessive sweating
iii) taking salty food
Which one is correct?
a) i and ii
c) ii and iii
4
...
ii) taking less fruits
b) i and iii
d) i, ii and iii
Biology
123
Which one is correct?
a) i and ii
c) i and iii
b) ii and iii
d) i, ii and iii
Creative question:
1
...
A is compared with a filter?
If Fig A is damaged or inactive what measure will you take to prevent it? Give
your opinion
...
The process, by which animal moves from one place to another by
their (it’s) own effort, is called locomotion
...
We will be able to know about structure of skeletal system, it’s
function and its way of protection
...
- Describe the role of skeleton in firmness and locomotion
...
- Explain the function of muscles
...
- Describe the cause, symptoms, remedy of osteoporosis
...
- Assume the cause of osteoporosis and arthritis
...
- Be conscious about the health / soundness of bones
...
Skeleton is the
frame work of our body
...
It gives
the definite shape to the body and protects
g
Sternum
the internal organs, such as : heart, lungs,
stomach, intestine, brain etc
...
All bones and other associated parts together column
constitute the skeleton which consists of
bones and cartilages
...
Bones are
remaining attached with the voluntary
muscles that helps movement of different
organs
...
Human skeleton is divided into parts, as- (1)
Exoskeleton and (2) Endoskeleton
...
g
...
(2) Endoskeleton : The skeleton of man means endoskeleton which can not be seen
from outside
...
Role of skeleton in firmness and locomotion:
Functions of skeleton: The skeleton does the following functions such as :
(a) Structure and firmness of the body- The skeleton forms the hard structure of the
body and gives a definite shape to the body
...
(b) Protection – Skull protects brain, spinal cord within the vertebral column or
backbone, lungs and heart within the thorax
...
(c) Movement and Locomotion: Hands, legs, shoulder or pectoral girdle and pelvic or
hip girdle help in movement
...
Due to
the attachment of muscles with the bones we can move the bones and we can move
...
126
Biology
(e) Storage of mineral salts – Bones store mineral salts (calcium, potassium,
phosphorus)
...
Bone – Bone is the modified form of connective tissue
...
The matrix of the bone is hard and
brittle
...
Bone cells are called
osteopath
...
Bone is mainly composed of
phosphorous, potassium and calcium different compounds
...
Living bone cells contain about 40% organic
and 60% inorganic substances
...
Due to the deficiency of these substances the normal growth of bones is
resisted / obstructed / hindered
...
These are relatively soft and elastic or
flexible
...
These cells are found solitary or pairs
and densely scattered out within the matrix
...
Matrix is composed of chondrin
...
In living cartilaginous cell the protoplasm is very transparent, with
round nucleus and cavity is noticed within the chondrin
...
All cartilages are enclosed by a layer of
fibrons connective tissues that is called perichondrium
...
So, cartilage looks white, bluish and glazy shining
...
Cartilages are found in different joints, or articulating surface of
some of bones
...
g
...
Work : Find out the differences between bone and cartilage
...
In every joint,
bones are joined firmly together by flexible elastic
tissues called ligaments
...
The joint helps in the movement of
limbs
...
Some of it is fixed, e
...
– intervertebral joint
...
g
...
Synovial joint: A bone joint is a joint where two bones
touch and make a simple synovial bone joint
...
A joint, which is
composed of a capsule, synovial membrane, a synovial cavity with a kind of lubrication
Biology
127
fluid or synovial fluid, is called synovial joint
...
Synovial joints have ligaments for holding the bones together collectively to form a
strong fibrous capsule
...
Types example – Bone joints are
of different types
...
Fixed joint – The bones are joined firmly, so it is immoveable example – joint of
cranium
...
Slightly movable joint – These joints are joined with one another still it has small
sliding surface
...
3
...
Example wrist joint ball
and socket joint
...
Hinge joint: The elbows, knees, joints of the finger are the examples of hinge joints
...
It can be moved in one plane only
...
Activities of Muscles: The muscular system consists of involuntary muscles of internal
organs and the wall of the blood vessels, cardiac muscles of heart and the voluntary
muscles are attached with the bones
...
Muscular
system performs various important functions such as :
- Movement of organs, helps, movement, placing the organs in orderly manner and
balancing
...
- The cardia muscles are of special type, it maintains the heart beat and blood
circulation
...
The skeleton constitutes
the structure of the body and muscular
system makes the covering of the structure
...
Muscle contraction is the result of
nerve impulses
...
This contraction and
relaxation of muscles, attached with the
bones, help in movement
...
The role of muscles in the movement of bones is described with an example : observe
how muscles work to bend or extend the elbow
...
The
biceps muscle is attached to scapula at the top and radius at the bottom
...
At that time triceps muscle relaxes
...
That means by the stimulation of voluntary
nerves the triceps muscle contracts and straightens or extends the radius and ulna
...
In this way we can bend and extend our arm by the
simultaneous contraction of biceps and triceps muscle
...
Tendon and ligament:
When we say to you that muscles remain attached
with the bones or one bone remains attached with
another bone with the help of a band
...
Muscles
are joined to bones by tendons
...
The tissues are composed of unbranched, wavy and
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129
shiny white fibers
...
The fibers are unbranched
and white in colour
...
Numerous fibres form
bundle
...
The outer surface of these
bundles is surrounded by areolar tissue and make a big bunch
...
The space between the bundles remains fibroblast cells
...
It is flexible but inelastic
...
The fibres of tendon are attached with the sarcolema of muscle fibres
...
Tendon is strong and has less possibility to tear or break than that of
muscle or bone
...
Bones are attached to each other by a thin cloth like soft but strong, elastic band like
structure
...
It is composed of the combination of white and yellow
fibres
...
Fine, branched net work of
elastic fibres remain scattered in this kind of tissue
...
These have elasticity and are composed of elastic protein
...
As a hinge attaches the door with its frame, in the same way
tendon and ligament are firmly attached to the bones
...
Draw the table in your note book and fill it up
...
Calcium and vitamin enriched food is essential for
the growth of bones
...
Generally elderly males and females suffer from this disease
...
Those, who lead lazy life, do less physical labour and are suffering
from arthritis, have the chance of being attacked with this disease
...
After reaching the menopause stage the density and thickness of bones decline
in female, bones become brittle
...
Diagnosis : The disease can be diagnosed by examining the density of the bone with the
help of density measuring equipment
...
Suddenly hip bones or any other bone fructures even or minor
shock
...
- Take skimmed milk and other diary products
...
Prevention:
- Taking food of vitamin – ‘D’ and calcium
...
- Take balanced diet
...
Prolong suffering with rheumatic
fever and are not treated properly may have the possibility of being attacked with this
disease
...
In case younger’s joint pain may be
symptoms of any other disease
...
Symptoms:
- Inflammation and pain in bone joints
...
- Get pain in articular movement
...
Remedy : The disease is not fully cured in elders
...
- To avoid hard labour
...
Biology
-
131
Take deep heat in the affected joint
...
Avoid pulse (dul) type of food
...
Live in the healthy environment
...
- Regular exercise
...
Work : Collect information about life style, in taking of food of the women who are
above 50 years
...
Exercise
Short answer question
1
...
Mention five functions of skeleton?
3
...
What are the characteristics of synovial joint?
5
...
Essay type questions
1
...
Multiple choice questions:
1
...
Tissues of tendon’s are –
i) white and glassy
ii) unbranched and waved
iii) fibrous and in cluster
Which one is correct?
a) i and ii
b) i and iii
c) ii and iii
d) i, ii and iii
Observe the stem and answer question 3 and 4
...
Doctor has said she is suffering from
osteoporosis due to calcium deficiency
...
Which one is the symptom of this disease?
a) increase the density of bone
b) bone becomes brittle
c) feel pain in waist
d) increasing muscle strength
4
...
12 years old Binita is healthy and restless
...
One day while she was running he fell down and her ligaments
of the leg injured
...
d) What type of co-ordination is necessary to carry out the activities done by Binita
– analyze it
...
a)
b)
c)
d)
What is tendon?
What do you mean by osteoporosis?
Explain why the cell structure of ‘x’ part is different?
How the co-ordination between x and y plays a role in movement, analyse it
...
These activities happen all together
...
In plants
there is co-ordination to perform all physiological process, such as: movement,
reproduction, metabolism, germination, growth etc
...
The co-ordination of plants and human is the matters to be discussed in this chapter
...
Explain the co-ordination system in animals
...
Explain the structure and functions of a neuron
...
Explain transmission of impulses
...
Explain irregular secretion of hormones that creates the main physical problems
...
Describe the nervous disorder’s cause, symptoms and remedy
...
Investigate the cause of physical disorders regarding hormones
...
Draw a leaflet or poster regarding the harmful effects of drugs or addition
...
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135
Coordination in plants
Like an animal cell, different physiological activities are simultaneously and
continuously carried out in a plant cell
...
So in the life of a plant, the coordination of physiological
activities is an essential act
...
In the life span of a plant in coordination with the time, stages in life cycle, such as
germination, growth and development, flowering, development of fruit, aging, dormancy
etc
...
The significance of weather and climatic factors on
the process is also notable
...
Despite the complexity and ceaselessness, these activities are
accomplished following some special regulation and system
...
How is this coordination maintained in all the activities? The growth and development of
plants, development of different organs in plants etc
...
The
substance, which controls all the activities, is called hormone
...
Some designate the
phytohormones as the plant growth substances
...
Every cell of a plant
has the ability to produce hormone
...
The main natural phytohormones are auxin, gebberellin, cytokinin, abscisic acid,
ethylene etc
...
Besides these hormones mentioned above, there are some other hormones which could
not be separated or identified
...
They mainly help
the activities related to the development of flowers and reproductive organs
...
Florigen is formed in the leaves and,
being translocated to the base of the petiole, transforms the vegetative buds into floral
buds
...
The chief phytohormones are mentioned below
...
Charles Darwin studied the effect of light on the coleoptiles of plants)
...
By performing experiments, scientists became assured of
that kind of chemical substance at the top of the coleoptiles which is responsible for that
type of movement
...
After the application of auxin,
root grows from grafted buds, prevents the premature shed of fruits
...
The rate of osmosis and respiration is increased
on the effect of auxin
...
Gibberellin: The causal organism of Bakanae disease of rice is a kind of fungus, which
causes an over growth of the rice plant
...
The substance is gibberellin
...
Elongation of internodes are influenced by the
phytohormone
...
If this hormone is applied to a
stunted plant, it grows more in length than a normal plant
...
Cytokinin : The phytohormone or plant hormone is found in fruits, cereals and water of
green coconut
...
They generally stimulate the
process of cell division being mixed in different concentrations with oxygen
...
At the
time of cell division cytokinesis occurs in a cell because of the effect of cytokinin
...
It helps the fruit to be ripened
...
Ethylene breaks the
dormancy in seeds and buds, and helps seedling to grow much in length
...
Ethylene accelerates the shedding of leaf, flower and fruit
...
A kind of auxin named Indole acetic acid improves the effectiveness of cambium
...
By applying auxin, the shedding of fruits is delayed
...
Growth
The effect of light and temperature on the development of different organs of plant is
remarkable
...
According to the opinion of some scientists, in
presence of light, the hormone auxin becomes inactive and so in the dark days,
Biology
137
concentration of auxin increases
...
The tip of plumule or radicle can feel the stimulus of gravitation
...
Owing to gravitation, the components of cell are translocated downwards
...
This is why gravitational movement is accomplished
...
This is why
new organs are developed by evolving of different components through different synthesizing
ways and the components of a cell moves downwards
...
The leaves of the plant are considered to be
the place of receiving stimulus at the photoperiod
...
But the long photo period is helpful for their flowering
...
The
rhythm of light and dark in a plant is called biological clock
...
1
...
For example, Garland chrysanthemum and Dahlia
...
Long day plant: Average daily phortoperiod of 12-16 hours is required for flowering
...
3
...
For example, Garden
Cucumber and Sunflower
...
If chilling is applied to the germinating seeds of many plants, their
flowering periods get forwarded
...
Scientists have proved the effect of temperature
on the flowering of plants
...
If 20- 50 C temperature is applied on the seeds after sowing, the normal
flowering occurs in them
...
affect the
growth of plants
...
Movement:
Like other living organisms, plants are able to perceive stimuli
...
Some
movements in plants happen because of growth and some other movements occur in
plants because of some internal and external stimuli
...
138
Biology
Movements in plants can be categorized into two: movement of locomotion and
movement of curvature
...
For example, this type of movement
is found in the gametes and zoospores of some fungi and
higher plants
...
In other way, the higher plants anchored in soil cannot
move from one place to another
...
This type of movement is called movement of curvature
...
are the examples of their movement
...
Among them
phototrophic movement is notable
...
Figure 10
...
Phototrophic movement or phototropism:
Phototrophic movement is a kind of movement of curvature
...
The movement
of stem towards light is called positive phototropism and the movement of root away of
light is called negative phototropism
...
Work 2: Test the movement of root towards gravity and present the results with reasons
...
What is hormone? you will know it after wards
...
Different research work has done about this matter
...
Ductless glands exercise control to each other
...
The matter is like that, activities of hormone
is considered as worker, but as a whole which worker works, where, how long he will
work all these are controlled by the manager, like that nervous system controls the
activities of hormones
...
If any ant gets a trace of food, it secretes
one kind of hormone from the source to its destination which is known as feroman
...
For this reason ants move in the same
Biology
139
path
...
Some insects can search its on own counter part of own
species
...
You may have seen to destroy insects by using feromen
...
This process is very environment
friendly to control the harmful insects
...
To regulate these
organs properly coordination and integration are necessary
...
For the activities of different organs co-ordination is needed, nervous system has an
important role to do it
...
The outer side of the world is the external
environment and the inner side of the body is the internal environment
...
These create stimulation at the
tip of the sensory nerves of ear, nose, tongue and skin
...
Some nerve impulses originate inside the
central nervous
...
Impulses which pass along sensory neuron fibres to the brain
...
Excluding nervous system there some specific chemical substances named hormones
takes part in co-ordination
...
At first there was an
idea that is a stimulating substance
...
Very small amount of hormones are
required to control particular physiological function
...
The influence of hormones on behavior of an individual, nature, transmission of
impulses is very important
...
So they are termed
as chemical messengers
...
Main function of the nervous system to carry
impulse to the different parts of the body, co-ordinates various activities of the organs
and maintains a relation with the environment
...
Brain is protected in the skull
...
Brain is the manager of the nervous system
...
As : a) Fore brain b) Mid brain and c) hind brain
...
They are
separated by deep furrows
...
The right hemisphere controls
the left side of the body and the left
hemisphere controls the right side of the
body
...
The left
lobe of cerebrum is comparatively well
developed
...
It is
covered by a membrane, called maninges
...
2 Human brain in Sagital Section
The exterior surface of the cerebrum is named
as cortex is composed of numerous neurons and is gray in colour
...
Spinal
cord is located in the vertebral column
...
That is why it is called white matter
...
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141
Cerebrum is the higher organ which receives nerve impulse and sends response (nerve
impulse) to the various organs of the body
...
The conscious activities, e
...
speech, vision, hearing,
intelligence, memory, thinking, will and activities voluntary muscular are controlled by
cerebrum
...
b) Mid brain or Mesencephalon : The upper part of the hind brain is mid brain or
mesencephalon
...
There is a cylinderical
part that is located at the back part of mid brain is pons
...
Its functions is to co-ordinate the activities of various
muscles and balance
...
Cerebellum: Cerebellum is localated at the back part of pons
...
Its exterior part is composed of grey matter and the inner part with white
matter
...
As : jumping and running
...
Medulla oblongata : It is the most posterior part of the brain
...
There are 12 pairs of cranial nerves, extend from the
cerebrum and medulla oblongata and within which pairs
of nerves originate from medulla oblongata
...
12 pairs of cranial nerves originate from the brain and
spread in different regions
...
The nerves are sensory or
motor or mixed in nature
...
It is protected by vertebral column
...
But their position is quiet
opposite to the brain
...
31 pairs of nerves originate from the spinal cord and passes through the hole
located in between the vertebrae
...
These nerves are mixed in nature
...
Nervous tissue:
The tissue that can receive stimulus from the environment and can transmit according to
make an appropriate response, is nervous tissue
...
Neuron is the basic functional unit of the nervous system
...
Cell body
a) Cell body: The part of the neuron which contains a
nucleus, cytoplasm remains bounded by plasma membrane,
round, oval, star shaped is known as cell body
...
b) Processes: A variable number of nerve fibres extends
from the cell body which is called processes
...
g
...
The number of dentrite in a cell
Figure: 10
...
(2) Axon : A long unbranched extended process originates from cell body is axon
...
Numerous dendrites and axons
together forms a nerve, the fatty layer in between neurilima and axon is called myolin or
myolin sheath
...
Generally it is interrupted at regular intervals
...
This uncovered part is
known as nodes of Ranvier
...
One neuron do not join directly to the next neuron cell
...
The sites or function of these gapes are called synapse
...
Nerve impulses transmit into the dentrite of next
neuron by a electrochemical process
...
The main function of neuron is to conduct nerve impulses
...
Work : Draw a labelled diagram of a neuron
...
No sooner his pupil
contracts
...
So the pupil
becomes small
...
Reflex action : Reflex action means sudden response or automatic reaction
...
This is the the result of reflex action We can not control the
reflex action according to the will
...
That is the immediate response to a specific stimulus is not controlled by spinal
cord instead of brain is called reflex action
...
That is a reflex action
...
Skin acts as a
receptor
...
It is the
Spinal cord
motor or efferent neurons
Figure: 10
...
Here impulse is transmitted from the
axon of the sensory neuron located at the grey matter of the spinal cord to the dendrite of
the motor nerve by electro chemical process
...
Then the
impulse from the dendrite impulse ultimately reaches to the muscles and the muscles
contract according to the command of the central nervous system
...
(2) Peripheral nervous system : 12 pairs of nerves from the brain and 31 pairs of
nerves from the spinal cord originate, divide into small branches and spread all over the
body
...
The cranial nerves
originate from the brain controls the functions of the organs, as : eye, nose, tongue, teeth,
face, heart, stomach etc
...
Autonomic nervous system: The organs, which are not controlled by us, are regulated
and controlled by autonomic nervous system
...
g- heart, intestine, stomach, pancreas etc are regulated by the autonomic nervous
system
...
Impulse transmission :
Numerous neuron fibres are connected to each other
...
The velocity of it is approximately 100 meter per second
...
These are called nerve impulse
...
As a result
neurons act as an impulse transmitter from the receptor centre to the different various
organs
...
So we can move our different
organs according to our need
...
When a sensory nerve is stimulated, it
transmits towards the brain then one can feel the
sense of touch, sight, pain etc
...
Say, a teacher is giving dictation and you are writing
...
This impulse reaches the sight centre of the brain
...
Such as centre of thought, memory etc sends message or impulses
to the voluntary muscles of the face
...
Here teacher’s
muscles involve in speaking are the effectors or response organ
...
This sound wave stimulates the ear drum, of the
student and that reaches to the auditory centre of the brain through the auditory nerve
...
Then the muscle
responds and the student starts writing
...
What is Hormone ?
There is a special kind of glands in different animals and in human
...
The secretions produced by the ductless glands or endocrine glands are known as hormone
...
Hormones are carried by blood
current and reache to the specific cells, influence the biochemical function within the cells and
Biology
145
regulate the biological process
...
But over and under secretion of hormones causes
various undesirable reactions
...
Pituitary gland : Pituitary gland or
hypophysis is situated beneath the brain
...
Because Pituitary gland
secretes several hormones
...
Though it
is the smallest in size but it is a very important
Pancreus
endocrine gland
...
Thyroid gland : Thyroid gland is situated at
the upper part of trachea
...
Protrusion of eye balls is caused due to the problems of thyroid gland
...
Parathyroid gland : Parathyroid glands are situated in the posterior part of the thyroid
gland
...
These
glands secrete parathroxine hormone
...
Thymus gland helps in the
growth of sex organ
...
The secretion of thymus hormone is thymoxine
...
Adrenal glands
regulate the essential metabolic process
...
These
glands secrete adrenaline hormone
...
The group of cell in islets of langarhans secretes insulin
...
Thus the
group of cells in islets of langerhans regulate in carbohydrate metabolism
...
The hormones secreted from the glands control development of sex
organs and secondary sexual characters
...
In mature male and female reproductive
organs produce testosterone and oestrogen respectively
...
So marine fishes are one of the main
sources of iodine for human being
...
It is found the place away from the sea, such as – the number of goiter patient
is high at the foot of the Himalayas, Nepal or in north region of Bangladesh
...
It causes rough skin,
oval shaped harmless face
...
A good effect can be obtained by taking
iodide salt, banana, sea fished, fruits, arum etc
...
These glands secrete the hormone insulin
...
If for some reason the pancreas fails to produce the required / adequate
amount of insulin then the level of glucose increases permanently in the blood much
above the normal level
...
This condition is called
diabetes mellitus
...
In type – 1
...
So the patient has to take insulin injection
...
In this situation the patient
has to take medicine orally, it helps pancreatic cells to produce adequate amount of
insulin
...
It is not an infectious or contagious disease
...
The symptoms are frequent passing of urine,
excessive thirst, excessive hunger, gradual loss of weight in spite of excessive eating,
feeling tiredness and weakness, disturbed vision, roughness of skin, delayed healing of
wound etc
...
But this idea is not
correct
...
But people, who lead
a lazy life, sedentary workers, that is who do not work physically and are obese or
overweight persons have a greater chance of developing diabetes mellitus
...
If a close family members, like father, mother, grand father, grand
mother suffer from diabetes mellitus, then there is a great chance of developing the
disease
...
Diagnosis and treatment of Diabetes mellitus: Diabetes can be detected by testing the
urine and the blood sugar level
...
According to the views of doctors, the disease can be
controlled by following three ‘D’
...
a) Discipline: Discipline is the medicine for a diabetic patient
...
Biology
147
b) Diet : Dietary restriction is one of the measures to control diabetes
...
By following doctor’s suggested food menu, one can get good result
...
On doctor’s advice, oral drugs
or inject able insulin should be taken regularly
...
In blood
so the patient becomes senseless
...
Stroke : Colloquial name of brain hemorrhage is called stroke
...
Generally arteriosclerosis and high blood pressure is the cause of brain
hemorrhage
...
Hemorrhage or blood clotting may happen
at any artery of the brain
...
If blood enters into the ventricle of
brain and skull of the patient may lead to death
...
Symptoms are–
- Vomiting, severe headache,
- Patient becomes unconscious within a few minutes
...
- Muscle relaxes
...
- Face turns red
...
By proper treatment some times the patient may survive
...
Then the diseased
patient becomes restless and gradually the paralysed organ restores firmness
...
Attached
paralysed organ muscles of (such as- hand) gradually get back its power of movement
but the patient loses the power of doing minute work forever
...
After
shock primary improvement is rapid
...
Sudden attack of nerves temporarily loses it activity
...
The nerves, which are affected
totally, lose their ability to work forever
...
In many cases exact cause of this disease can not be ascertained
...
Take measure to keep high
blood pressure under control, after getting back the sense surgical operation can be done
if it necessary
...
According to the necessity or demand arrangement
can be made to feed the patient by using the tube
...
On gaining sense the patient is to be
encouraged to move by his own or her
...
Prevention : Avoid smoking, keeping high pressure under control, diabetic patient
should take medicine regularly, keep free from anxiety and leading a normal life
...
When there is damage in a part of the brain, then stimulation receiving
muscles loses its activeness
...
Generally stroke is the cause of paralysis
...
Nerve disease, damage of spinal cord may also
be the cause of paralysis
...
In may cases the
patient becomes unconscious
...
Only because of this
disease the diseased person losses his ability to work temporarily and fell on the ground
with convulsive movement
...
The main cause of Epilepsy is yet unknown and undiscover able
...
Ischemic stroke patient suffers from fainting disease
...
People of any age may
suffer from this disease, but it is extensive 5-20 years old people
...
Generally the disease starts after the
age of 50 years
...
Nerve cells produce a substance called dopamine
...
Their dopamine producing cells gradually destroy
...
So the muscle losses its
effectiveness
...
Parkinson disease gradually turns severe: At the prelimary stage of the disease it
begins with tremor and patient feels trouble to move leg or foot
...
Biology
149
Work : Try to investigate the cause of physical distress, difficulties created by hormonal
problem and make a investigatory report on it
...
Influence of tobacco and drugs in co-ordination :
In Bangladesh tobacco ganja, charas bhang, affim, morphin, cocaine, alchol and heroin
etc are known as addictive substance
...
These substances create addiction
...
There is many reasons for drug addiction in humans
...
Use of tobacco, chewing jarda or smoking increases nicotine level in blood
...
To meet this demand peoples become addicted of smoking and using jarda
...
Hands, legs and head trembles
involuntarily
...
Addiction creates bad effect and influence on nervous
system
...
His thinking capability gradually destroys only because of
addition
...
Excess addition makes him unconscious or senseless and fall here and there
...
So one can get rid of that
bad habit by taking treatment from rehabilitation center
...
Harmful effects of addiction : The intake of addictive substances may cause harmful
effects
...
Measures to get out of this situation :
- Increase wide spread of moral education
...
- Stop easy availability of addictive substances
...
- Initiate social mobilization and strongly in force laws regarding addiction
...
Take the assistance of
rehabilitation center if it is necessary
...
Day by day its field of work is
widening
...
Work : Draw a poster or leaflet regarding the bad effect of tobacco and addictive
substances and place it before the students in the class room
...
What is phytohormone?
2
...
What is nervous system?
4
...
What are the causes of paralysis?
Eassy type question
1
...
2
...
What hormone is secreted by thymus gland?
a) Thyroxine
b) Parathyroxine
c) Thymoxine
d) Thyrotrapine
2
...
ii) secretes insulin hormone
...
Which one is correct?
a) i
b) i and ii
c) ii and iii
d) i, ii and iii
Biology
151
On the basis of the following diagram answer the question 3 and 4
...
Which one of the following is applied to ‘A’
...
phototropism
c
...
geotropism
e
...
Which one of the following is applicable in the development of a lateral bud if the
apical one is cut off
...
auxin
c
...
gibberellin
d
...
Ohona observes different types of plants going to visit an agricultural farm with her
father
...
Moreover, she observes that flowering is not being accomplished in some fruit trees,
and some fruits being immature are falling off the trees
...
What is biological clock?
b
...
What are the causes of the problems found in the fruit tress mentioned in the
stem above?
d
...
2
...
d) The structure and nature of this cell is different- analyse it with your opinion
...
Organisms give rise to other
organisms of the same kind in life time and then continues its generation
...
Diversified reproductive processes are being
observed
...
At the end of the chapter we will be able to
...
x Describe the functions of a flower as a reproductive organ
...
x Explain the asexual and sexual reproduction of animal
...
x Make differences between the external and internal reproduction
...
x Describe the role of hormones in reproduction
...
x Explain the mode of transmission, prevention and remedy of AIDS in human
body
...
x Can raw the poster and leaflet for the prevention of AIDS
...
Biology
153
Concept of reproduction in organisms and its significance
Death is inevitable for life if it is born
...
But actually is not happening because in one hand
organisms are dying on the other hand organisms are also reproducing
...
The process through which organisms produce
their offspring is called reproduction
...
Generally in lower organisms,
sexual reproduction does not occur but some lower organisms reproduce sexually
...
In sexual reproduction, two reproductive cells of opposite characters are fused
...
Two types of reproductive cells can be produced in the same flower or in the
same body
...
They are monoecious plants
...
The precondition of developing of any reproductive cell is that germinal mother cell will
have to divide through meiosis
...
Later, zygote being divided
repeatedly through the process mitosis develops the new body of the newly born
organism
...
An organism this
way also maintains the flow of its future generations
...
From a virus or bacterium up to human beings, all
organisms maintain the existence of their species by reproducing their new generations
...
This is why when a lower organism does its reproduction through cell
division then an organism of higher level accomplishes its reproduction through the
complex process of sexual reproduction
...
A flower is a reproductive
organ of a higher plant
...
They directly take part in the
reproduction
...
The flowers, which have
five whorls, are called complete flowers
...
When both androecium and the gynoecium are present in a
flower, it is called a bisexual flower
...
If both androecium a gynoecium are absent
in any flower, it is called a neuter flower
...
The other
parts or whorls of a flower are arrayed consecutively on the floral axis one after another
...
Calyx: The outermost whorl of a flower is called calyx
...
Each of the part of calyx is called a sepal
...
Their main function is to save the
inner parts of a flower from the sun, rain and attack of insects and pests
...
as the medium of accomplishing pollution
...
1 Different types of flower
Corolla: It is the outermost-but-one whorl of a flower
...
If the petals in a corolla are separate from each other, the
term polypetalous is used then
...
Corolla usually looks colourful
...
Bright colourful corolla attracts animals – birds,
insects etc
...
Sometimes insects draw nectar sitting on the corolla of
a flower
...
Androecium: It is the third whorl from outside of a flower, and it is an essential whorl
...
In an androecium, there may be one or more
stamens
...
The part of a stamen, which connects the anther to the filament, is called connective
...
A pollen tube is produced from a pollen after
germination
...
The male gametes
directly take part in the process reproduction
...
When the
stamens with all the filaments merged together into a tube like group, it is called
monadelphous, such as in Chinese hibiscus
...
When anthers are united into a single group, it is
called syngensious
...
Fig: 11
...
Monodelphous b
...
Polydelphous d
...
Epipetalous
Gynoecium: The portion of gynoecium is at the centre of a flower
...
A gynoecium may be structured with one or more carpels
...
When a gynoecium is formed
with many more carpels and is completely merged with each other, then it is called,
syncarpous and when they are separated, it is called polycarpus
...
Within the ovule, female reproductive cell ovum is produced
...
Work 1 : Observation of different whorls of a flower
...
Work 2 : Separating the ovary from a flower, collect a transverse section with a blade
and place them aesthetically on the piece of blotting paper
...
Inflorescence: All of you have seen clusters of flower arranged in a small branch of a
tree, following some special orders of arrangement is called inflorescence
...
It is called peduncle on which
flowers are orderly arranged
...
An
inflorescence plays important roles in the process
C
pollination
...
The two issues are addressed below
...
Pollination is a precondition for the
development of fruits and seeds
...
Pollination is of two
types, such as, self-pollination and crossFig: 11
...
Cross pollination
1
...
For example, Brassica, cucumber and Datura usually
pollinate through this way
...
The plant that develops in that way of pollination
cannot make changes in their characters and so the features of a species can be
maintained
...
No new characters appear in the
new generation of plants
...
The
ability of adaptation in the new plant is reduced and once this species can be extinct
...
Cross-pollination: When the attachment of pollen occurs in between two distinct
flowers of the same species, it is called cross-pollination
...
New characters emerge through cross-pollination
...
So the new
species is ordained to pass its life on earth
...
The plant,
which grows from that seed, is also with the new characters
...
As it is a matter of carrier dependent process, pollination may not
be ensured and large waste of pollen is a consequence of this type of pollination
...
Biology
157
Medium of pollination:
In most of the cases, a medium or cues accomplishes the
transfer of pollen
...
Air, water, insects and flies, birds,
vampires, snails and even men may be the media of
pollination
...
Then pollens
get attached to the carrier at that time when the carrier
sits on the lap of the flower causing the pollen get
attached with it
...
Fly pollinated flowers are big in size with coloured
nectar secreting glands
...
For example, Chinese
hibiscus, Squashes, turnips etc
...
Air pollinated flowers are lightweight and without nectar
secreting glands
...
Their stigmas are sticky form a
structure like a feather branched will to attain pollens
from the air
...
No fragrance is with them
...
Mature male flowers being detached from the petioles
float in the water and after coming in contact with the female flowers, they immediately
accomplish pollination
...
If they are small, they are arranged in
the inflorescence
...
Fragrance may be present or absent in
them
...
Microsporogenesis
A pollen is the first cell of the gametophyte
...
The nucleus of
the pollen gets divided through mitotic division
and two cells, one large and another small, are
formed
...
The tube cell
turns into pollen tube and two male gametes are
produced
...
158
Biology
Megasporogenesis
Near the micropyle being nourished in the nucellus of
an ovule, a cell starts to become larger
...
The
cell divides into four haploid cells through meiotic
division
...
Growing gradually the larger cell
matures into an embryo sac
...
The nuclei are evolved as the nucleus divides
...
Next, these two nuclei consecutively divide twice and result in four nuclei
...
The nuclei in the two poles turn into cells
with some amount of cytoplasm
...
In between the
cells, the one occupying the middle place is the
ovum, which is little larger
...
The cells in the opposite pole to the egg apparatus
are called antipodal cells
...
Fertilization:
Trough pollination, mature pollen lands on the
stigma of a carpel
...
Once the tips of the
extended pollen tube entering into the
embryo ejects two male gametes in the
embryo sac
...
Another male gamete mixing
with the secondary nuclei develop
triploid endosperm cells
...
This phenomenon is
called double fertilization
...
Two cells are produced after its first division
...
A zygote divides
transversely
...
The division of these two cells
continues side by side
...
The suspensor also
gets developed concurrently
...
The cells in an endosperm
are triploid that means they posses three sets of chromosome (3n)
...
As the seed germinates, a complete
sporophyte is developed
...
Origin of fruits: When we think about fruits in our mind appear the images of mango,
jackfruit, lichi, banana, grape, apple, guava, sofeda etc
...
Bottle gourd,
gourd, Jingha, pointed gourd are also fruits
...
In fact, they are all fruits
...
Fertilization ignites stimulation in
ovary to make the way of developing fruits steadily and ultimately, ovules are turned
into seeds
...
If only the ovary turns into a fruit, it is called true fruit
...
When along with the ovary, other parts
of a flower get mature, this type of fruit is called false fruit
...
All the true and false fruits are grouped into three categories:
fleshy fruit, aggregate fruit and compound fruit
...
(1) Asexual
reproduction and (2) Sexual reproduction
...
Asexual
reproduction occurs in different ways
...
(2) Sexual reproduction : The process through which two animals of opposite sex
(male and female) compete their reproduction by means of producing male and female
gametes, fertilizes and produce offspring is called reproduction
...
It is a universal
biological process
...
Fertilization occurs by the fusion of that is called fertilization
...
The is cell is formed by the fusion of nucleus is zygote
...
Each of the sperm and ovum contains haploid number of chromosome it
160
Biology
signifies it carries (one set of chromosome)
...
Maturity of
sperm and ovum is the precondition of fertilization
...
It happens only with the matured / full grown sperm
and ovum of some species
...
Once an ovum is
fertilized it will not fertilize again
...
(1) External reproduction and (2) Internal reproduction
...
But exception are there, such as : sharks and different fishes
...
This fertilization occurs introducing
sperms of the male into the female reproductive organ
...
Some basic significance of fertilization : Restoration of diploid chromosomes within
the embryo accamulates heriditory characters of both male and female, makes the ovum
active for its development
...
These characterises combine, determine the sex of the embryo
...
Maternal male
reproductive cell
Or
Male stem cell
Sperm
Sperm
Zygote
Maternal female
reproductive cell
Or
Female stem cell
Development
Ovum
Ovum
Figure : 11
...
For the continuity and restoration of hereditary, reproduction is essential
...
Man is unisexual, so that male
and female reproductive organs are present in different individuals
...
It acts as a chemical messenger and is transported all
over the body organs through blood, help in chemical reaction and controls different
metabolic and physiological processes
...
Over secretion and in deficiency of these
hormones create disturbance in different function
...
Reproductive hormones secreted from endocrine glands within the body are described
below
...
Growth stimulating hormone and producing hormone are produced by the pituitary
gland
...
Besides, these hormones
regulate the contraction of uterus
...
It
regulates metabolic function ensures physical and mental development, sexual
characters
...
Testeron hormone secreted from
testis and androgen helps to produce sperms and sexual secondary characters, such as:
deepening of voice and growth of beard
...
These hormones cause the development sexual characters, menstruation,
enlargement of the well of uterus for implantation of the embryo and placenta
...
(singular of ova)
...
When the baby takes birth their reproductive system remains tender or immature
...
Hormones play a significant role in this process
...
The transitional period adolescence indolence and the
youth is named as puberty
...
Both inner and outer changes occur, such as: growth of extra hair on the face,
deepening of the voice, widening of shoulder etc are the external changes
...
In this stage of puberty usually starts
monthly discharge of blood or menses from the uterus at regular intervals
...
After 1-2 years of puberty girls gain the ability of
reproduction
...
It continues up to 40-50 years
...
Here it is mentioned that menstrual cycle remains temporarily stopped
during pregnancy
...
Marriage is a social, spiritual and a family ties
...
They become intimate to each other unhesitantly
...
There should be a specific time limit
to get marry
...
As a result early marriage
162
Biology
causes a girl pregnant in immature age
...
Sexual reproduction occurs by physical relationship in between husband and wife
...
A sperm
has a tail which helps it to swim into the female reproductive system
...
This fusion is called fertilization
...
In this
way internal fertilization occurs within the
human body
...
By
the fusion of these haploid sperm and ovum a
diploid zygote is formed
...
Immediately after the fertilization, cell division begins in the zygote
...
At the last stage of cleavage the growing embryo arrives in
the uterus
...
The changes that happens in the uterus is very important for the development of the
embryo
...
The embryo has to be embedded with
inner wall of the uterus
...
Wall this
process is called implantation or conception
...
Time between the implantation and child birth is called
pregnancy
...
The embryo or
fetus develops in the uterus for 38-40 weeks
...
Implantation is completed within 4-5 days after reaching the
embryo in the uterus
...
In this way a
temporary unseparated organ is formed between the fetus and endoderm of mother’s,
uterus
...
The embryo is implanted with the uterine wall with the help of placenta
...
Embryo needs food for its growth
...
are transferred from maternal to fetal blood
to nourish the developing embryo
...
The dissolved
oxygen in the blood of the maternal blood diffuses into the fetal blood and exchange
carbon di-oxide from the fetus to the mother
...
In this way the waste products are eliminated
...
Hormones protect the embryo and helps in normal development
...
During pregnancy exchange of
waste products and essential materials which are exchanged between the mother and
fetus through placenta
...
The embryo is attached to placenta
by a tube called the umbilical cord
...
Basically it is a tube
through which exchange of different materials occur between mother and fetus
...
Embryonic membrane : The embryos of each species have a series of embryonic
membrane which are essential for easy, normal and safe development of the embryo
...
Embryonic membrane protects the fetus (embryo) and controls other important action
...
11
...
At the same time mother’s
anterior pituitary and placenta begins to secrete two hormones
...
The hormones actively promote uterine contractions at regular
intervals that results pain
...
At the last stage of
child birth the embroyonic membrane bursts and fluid enclosed by the membrane comes
out and the fetus or baby push out of the uterus that means child takes birth
...
At
present AIDS is well known as a killer disease of the world
...
Taking from the first alphabet of Acquired Immune Deficiency syndrome the
disease I named
...
5 million people are infected by AIDS
germ
...
According to world health organization
this disease is spreading about 164 countries
...
This virus destroys
white blood cells causes obstacle in antibody
formation, that results the gradual shortage white
Fig
...
14 Structure of HIV
blood cell and antibody
...
It destroys the victims immune system
...
Because till today there is no effective medicine
discovered to regain the immune system completely
...
Causes of AIDS : A healthy person can be infected by this life threatening disease are as
follows such as –
1
...
Transfusion of
blood is necessary such as – blood loss due to accident, excessive bleeding at the time of
child birth, anemia, pthallasamia, cancer etc
...
2
...
A baby may be infected
from HIV infected mother during breast feeding
...
The disease may transmit to a healthy person Such as – Sharing of infection needles,
syringe or other/surgical operation related instruments etc
...
Trans placement of HIV infected organ or tissue in the body of healthy person
...
Before it can not
be comprehend that infected person is the carrier of this disease
...
- Fever for more than one month for unknown reason
...
- Pain in armpit, neck and face become rough
...
Such as : face, eyelid, nose etc
...
Prevention AIDS : You have learned earlier about this disease
...
- What is the necessity to prevent AIDS
...
Write the measures of prevention on the black board and make a summary of it
...
Biology
165
Exercise
Short answer question
1
...
What is uterus? What is its functions?
3
...
What measures should be taken to prevent AIDS
...
Explain the function of hormones in reproduction
...
Why is a flower called the reproductive organ?
2
...
Multiple choice question
1
...
Chinese hibiscus
b
...
Cotton tree or shimul
d
...
The air pollinated flower is
...
large in size
...
with undivided stigma
...
without nectar glands
...
i & ii
b
...
ii & iii
d
...
Which one of the stem turns into a seed?
a
...
O
c
...
Q
4
...
M & Q
b
...
M & N
d
...
a
...
What is indefinite inflorescence?
c
...
d
...
2
...
Recently with change of his
physical and mental changes his voice becomes deep
...
a) What is placenta?
b) Why AIDS is called a fatal disease?
c) Explain the cause of that events happened in Ridoy’s body?
d) Explain what are the role of the elders towards Ridoy
...
We will learn from this chapter how traits from
both the parents are transmitted to the offspring
...
At the end of this chapter, we will be able to:
x Explain the concept of heredity
...
x Explain the passing of the behavioural characteristics from generation to generation
...
x Explain the replication of DNA
...
x Explain the necessity of DNA test
...
x Explain the causes and results of genetic disorders
...
x Describe the natural selection theory of evolution
...
x Determine the differences between the similar and dissimilar features of mother and
father
...
168
Biology
All the organisms in the world are characterized with their own unique features
...
This natural
principle is applied to all organisms in the world
...
This
way the characteristics of species are maintained in offspring through generations
...
In depth discussions and researches concerning heredity are done in the
special branch of biology called genetics
...
Components carrying (heredity materials) behavioural features to the offspring
from generation to generation
The features of parents are transferred to their offspring through heredity materials
...
These are discussed below:
Chromosome: The main heredity material is chromosome
...
The scientist
Strasburger in 1875 first discovered chromosome
...
In length a chromosome may be form 3
...
00
micron (1micron=1/100mm) and in width 0
...
0 micron
...
Colours of human eyes, nature of hair, compositions of skin etc
...
This is why
chromosomes are designated as the physical basis of heredity
...
It is usually a double
stranded spiral structure of polynucleotides
...
In it
there are five carbon sugars, nitrogen bases (adenine, guanine, cytosine, thymine)
inorganic phosphate
...
DNA
is a stable substance in a chromosome
...
Nitrogen bases are of two types, such as,
purines and a pyrimidine
...
Adenine of a strand bonds with a thymine of another strand
by two hydrogen bonds, and guanine of a helix connects with a cytosine of another helix
by three hydrogen bonds
...
So a strand of DNA is complementary to another strand but not just as the
same
...
So the length between the two adjacent nucleotides is 3
...
Two strands of
Biology
169
polynucleotides in DNA are positioned antiparallelly
...
Bases are connected flatly and horizontally in the position from the
main axis
...
In
fact, DNA is a precise thread but in prokaryotic cell DNA is usually circular and the
surface area would be some microns to centimeters
...
DNA
is the main component and chemical carrier of heredity
...
RNA
RNA stands for ribonucleic acid
...
It is
composed of 5 carbon ribose sugar, inorganic phosphate
and nitrogen bases (adenine, guanine, cytosine and uracil)
...
In some viruses
(tobacco mosaic virus) DNA is absent
...
In this situation, RNA serves itself as the hereditary
material
...
1 DNA
The unit of controlling all the visible and the invisible signs and characters of organisms
is called gene
...
The
location of a gene throughout a
chromosome is called locus
...
For a specific
character, a gene is responsible
...
In other cases, a gene controls
more than one character
...
The number of gene in different organisms
is not the same
...
Genes are arranged in a common principle alongside from one end to another end
...
The character,
which is expressed in the first generation form the parent is called, dominant character
and the character, which does not express in the first generation but is expressed in the
second generation, is called a recessive gene
...
Gregor Johan Mendel is called the father of genetics
...
DNA replicates in a half-conservative way
...
At the end, a new
strand, combining with another old strand, forms the structure of a
molecule of DNA
...
This principle is known as semi-conservative method
...
Work: The teacher will ask the students to demonstrate a diagram of a DNA after
drawing it in a big piece of paper with a pencil
...
In Bangladesh, along with evidence, witness, eyewitness dependent judiciary system,
DNA has opened a new window of ensuring true justice
...
Besides, the
name DNA typing or DNA testing is also used in some practices
...
Bone of a person, teeth, hair, blood,
saliva, semen can serve as valuable organic specimens
...
In this
process, first forms of specimen DNA should be isolated
...
Through a special method called
small electrophoresis agarose or polyaxialamaid gel, DNA fragments are separated
alongside their length
...
This method is called DNA finger
printing
...
Biology
171
Determination of human sex (gender)
In human and other mammals sex is determined the same way
...
e
...
Among them 22 pairs or total
number of 44 are autosomes and the remaining pair is sex chromosome
...
The two sex chromosomes are marked with X and Y
...
In women, in the diploid cells both sex
chromosomes are X i
...
XX
...
Both the chromosomes are long in structure, rod shaped but chromosome
Y is little shorter than the chromosome X
...
But in case of a man at the time of the
formation of sperms, half number of sperms contain X chromosome and other half
number of sperms contain Y chromosome
...
So, zygote can be having both the chromosomes as type X, or
can be having one X and the other one Y
...
e
...
If the principles and orders of determining human sex are pondered over well, we will
find that in determining sex, a mother plays no role because a mother always produces
eggs containing only X chromosome
...
At the time of conception, the
type of sperm, that will fuse with the egg, determine the sex of the offspring
...
If the Y
chromosome bearing sperm fuses with an egg, the zygote would bear chromosomes of
both the type X and Y
...
The result would be the
offspring as a son
...
For these erroneous concepts, mothers
have to endure many mental and physical oppressions
...
The issue is shown through the figure
...
To
identify colour, we have pigments in our optical nerve cells
...
If someone lacks a single pigment then he would not be able to
differentiate colour red and green
...
For
lacking of more than one pigment besides red and green, the patient cannot differentiate
the colour blue and yellow
...
In comparison, very
few numbers of women suffer from this problem
...
Advice from a registered ophthalmologist can be a
worthy solution to cope up with the situation of colour blindness
...
Because of this disease, red blood cells are disintegrated
...
This disease genetically passes from generation to generation
...
It is guessed
that every year 7000 babies are born with the problem Thalassemia and at present the
number of patient may be one lakh
...
Thalassemia is caused for the disintegration of the two genes
related to the above mentioned proteins
...
This type of disease is found at large in the community of South East Asia,
Middle East, China and Africa
...
Though this type of
disease is more found in the people of Mediterranean region, some people having
Africans, Americans, Chinese origin may also suffer from the blood disease
...
On the basis of the inherited gene,
Thalassemia is grouped into two categories
...
This type of body does not
express any sign of Thalassemia but functions as a carrier of Thalassemia genes
...
The patient must not have to eat iron
reach fruits and medicine, as they being accumulated may cause much harm to other
body organs
...
Besides, if the liver is badly affected other diseases or jaundice can be
initiated
...
The organisms who are surviving now, all
emerged in different times in the biosphere
...
Dinosaurs became extinct thousands of years back
...
In
the span of some thousands years of time, the species of living organisms for their
emergence and survival change themselves furnishing new changes with them and is
called organic evolution
...
5 Diversity in the species dog
Charles Robert Darwin was a British natural scientist
...
M
...
Beagle and traveled to many different countries in the world
...
Later
being familiar with the population theory of Thomas Robert Malthus, Darwin started
thinking on the struggle for surviving of organisms
...
A
dweller of Brunei natural scientist Alfred Russell Walles sent his write up on the theories
of population control to Darwin, and those write up inspired Darwin to postulate his own
concept
...
He mentioned the opinions of Walles on the changes of animal population through
natural selection before the members of the London Linnaeus Society
...
Twelve hundred copies of this book were sold on its first day of publication
...
Within the same species, even within the offspring of the same parents
differences are found
...
As a result of these changes, organisms are different
from each other
...
It is the intrinsic ability of organisms
...
A Catla
fish in the river Halda of Chittagong lays 3-5 lakhs eggs per season
...
The same way, an adult Hilsha in the river Meghna can lay, irrespective of size,
3
...
It is guessed that in a favourble condition very few number of
Jatkas at last get the scope of becoming a grown up Hilish
...
Darwin presented a calculation
describing if all the elephants survive being born from a pair of elephants in 750 years
the total number of elephant would be 19 lakh
...
From the example it is clear that the rising of the number of any organism continues
without any inhibition, any one species would make the world covered by the members
of the species
...
For anthropogenic causes such
as excessive acquisition, environmental pollution etc
...
It is guessed that in case of not catching of puna for Ruhi in
favourable condition in our rivers the number of Ruhi, Catla and Hilsha fishes would
highly be multiplied
...
This is why struggle of organisms for
survival is inevitable
...
For the survival of organisms the following
matters draw our special attention
...
For every organism, food and dwelling place are very limited
...
It has been found if some deer are
released on an island, they grow there, reproduce there and rapidly their number
continues to rise
...
2
...
The inter-species competition between the
different members of the same species goes on
...
3
...
Flood, drought, storm, rain,
excess heat, winter, volcanoes, tsunami, tornado, earthquake etc
...
Lots of organisms are destroyed with the natural
catastrophes
...
176
Biology
Natural selection
According to Darwin, the organisms which gain success in struggling by being changed
in physical characters have won the fight
...
In other way, the organism
which cannot introduce new changes in them, are nominated or selected by the nature
...
The animal of the past dinosaur became extinct in spite of its
being much strong
...
Survival of the fittest
The characters, nature and the trends in organisms and in their offspring are the diversity
expressing favour and make the organisms to cope up with the environment
...
Conversely, the organisms,
with adverse diversity in the struggling with the passage of time ultimately, are
destroyed
...
In the nature, many plants and animals attain some abilities
being well adapted
...
In desert, many
plants adapt with some striking techniques to store water, introduction of new mummery
to protect them
...
Significance of evolution in surviving of species
Through evolution at the emergence of new species, many other species are lost in the
passage of time
...
It has been found that
the species which possess the more ability to adapt through the way of evolution can go
far
...
In most of
the cases, it is called adaptation
...
What is RNA?
2
...
Why is a chromosome called the physical basis of heredity?
4
...
What does Thalassemia mean?
Essay type question
1
...
Multiple choice question
1
...
DNA
b
...
gene
d
...
Which one does RNA contain?
i
...
inorganic phosphate
iii
...
i
b
...
ii & iii
d
...
In the state of X mentioned in the stem, what would be the number of chromosomes?
a
...
44
c
...
22
4
...
X, XY
b
...
Y, XX
d
...
He has two daughters
...
Recently, as he
has given birth of a baby daughter, he has become anguished at his wife
...
a
...
What is replication?
c
...
It is irrational that Sifat got anguished with his wife
...
2
...
He saw in spite of their belonging to the same species, they look different in
size, colour
...
His
father gave him the concept on evolution and adaptation when he became interested
to know this
...
What is locus?
b
...
Explain the causes of difference with the animals seen by Sohel
...
What will happen if the organisms found in the stem first are left in the
environment where the animals of second group found?
178
Biology
Chapter Thirteen
Environment around life
The environment of an organism means all the living and non-living components around
it
...
The
steps that the organisms take in the different stages of the survival for the maintenance of
life, have also effects on the life of the other organisms living in the same environment
...
At the end of this chapter twelve, we will be able to
x Explain ecosystem
...
x Explain two objects: food chain and food web
...
x Compare the relationship between energy performances in between more tropic levels
...
x Explain biodiversity and types of biodiversity
...
x Explain the interactions and inter dependence in between different organisms in
maintaining balance in environment
...
x Analyze the importance of conservation of environment in maintaining the balance in it
...
x Identify the causes of pollution of all the elements of a specific environment
...
x Perceive the contribution of the components of an ecosystem to the maintenance of
balance of the environment
...
Organisms actively collect their components from the non living
world and carry on their life, and after death being waste substances or getting mixed
with the environment again send back all the elements to the environment
...
For
the whole living world (plants and animals) the oxygen, required for respiration, comes
from the oxygen produced through photosynthesis
...
Herbivorous animals survive by eating
different parts of plants in different ways
...
Waste materials from all
animals get mixed with the environment again
...
Some bacteria and
microorganisms do this disintegration process
...
The exchange of energy and materials, between plants and animals and both the living
and nonliving substances, is called interaction
...
A place like this one, this world is an ecosystem
...
For the source of different elements for nutrition and other physiological
activities, soil, air and water are required
...
Each of these main components is
composed of some other small components
...
a) Non-living matter: The non-living matter harbors the habitats of living organisms,
provide them with oxygen for respiration and supply some nutrient components as
well
...
i) Inorganic matter: Water, air and mineral substances in the soil, which have not
evolved from any living body rather before the emergence of organisms they existed,
and they are the inorganic components of an ecosystem, such as calcium, potassium,
iron, nitrogen, oxygen and carbon dioxide etc
...
They are generally termed as humus
...
The organic matters
are more nutritious for plants
...
Most animals also like soil composed of rich humus
...
With all their components, weather and climate of any locality develop
...
c) Living organisms: Living world is the active component of ecosystem
...
Living components of the
environment are of three types: 1
...
Consumers 3
...
1) Producers: Green plants, in presence of sunlight obtaining carbon dioxide from the
air and absorbing water from the soil, produce their chief food carbohydrates
...
The whole living world directly or
indirectly depends on the photosynthesis process for their main food carbohydrates
...
This is why photosynthesis is the production process of an
ecosystem
...
On the other way, these green plants
are called autotrophs because they can produce their food themselves, they do not
depend on others for their food
...
They directly or indirectly depend on plants for their food
...
The animals, which directly consume plants as
food, are called herbivorous
...
Grasshoppers,
hens, cow, goats and deer are the examples of herbivorous animals
...
They are carnivorous kind of
animals
...
The animals,
which eat secondary consumers, are also carnivorous
...
These are a kind of
animals who like more to eat dead bodies of other organisms than the living body of
them, for instance, fox, hyena etc
...
3) Decomposers: The microorganisms, like some bacteria and fungus, get their food
from wastes of plants and animals and their dead bodies, and as a consequence, they
get mixed with the soil and water by being decomposed
...
This is why these microorganisms are
called decomposers or transformers
...
The deeper relationship,
between the living organisms living in the ponds and the non-living substances there,
can be conceived
...
The living components are producers, consumers of first level, consumers of tertiary
level and different types of decomposers
...
2 A pond ecosystem
Producers: The producers are the photosynthetic algae and plants of shallow water
...
Phytoplankton, green algae and
other aquatic plants, which produce food through the photosynthesis process, are called
primary producers
...
are the consumers of first level
...
These consumers cannot produce their food
themselves
...
Consumers of secondary level: Small fishes, some aquatic insects, toad etc
...
They cannot produce their food themselves and cannot
182
Biology
consume directly the primary producers
...
Consumers of tertiary level: Some small fishes, prawns etc
...
Shoul, Bhetki, Boal
like big fishes and stork are the consumers of tertiary level
...
They live there floating in the water or at the bottom in the muddy habitat
...
The producers in the pond can again consume the substances
decomposed by the decomposers
...
If they do not produce food, herbivorous animals and other carnivorous
animals may die in want of food
...
For instance, the green grass on a field is the primary producers and grasshoppers live on
some plants of the grass
...
The toad eats
grasshoppers and the snake eats the whole toad as its food
...
In this case, food chain may be formed according to the flowchart
...
(1) Predator food chain: The food chain, where organisms of the primary level are of
the smallest size and consecutively consumers of higher level prey the organisms of
lower level and at last eat them, is called predator food chain
...
(2) Parasitic food chain: Parasitic plants and animals in most of the cases derive their
food from the host much larger in size than they are
...
In this type of food
chain, primary producers may not be always at the beginning level
...
Man----------- mosquito-----------Dengu Virus
Biology
183
(3) Saprophytic food chain: If any food chain is stretched from the dead organisms to
the different tropic levels, then it is called a saprophytic food chain
...
Parasitic and
saprophytic food chains are always incomplete since there is no producer in them
...
So, the food chains of an ecosystem are based on the activities of
the photosynthesis of the producers green plants
...
This way some food chains collectively may form a net or web like structure
...
This is a true phenomenon for both the terrestrial and aquatic
ecosystem
...
In the diagram above, it is found that primary producers algae directly provide
zooplanktons and small fishes with their food
...
This big fish also eats the small fishes
...
Here
five organisms have developed some food chain in different ways
...
Total five food chains are found in the food web mentioned above
...
algae
small fish
2
...
algae
small fish
4
...
hawk
184
Biology
Work: Write down the food chains in the food web mentioned in the figure 13
...
A plant uses a part from the food it
produces itself, remaining food is stored in the plant body
...
After the death
of these plants and animals, decomposers transform them into inorganic substances by
using them as their food and the decomposers return the substance to the states from
where they are taken
...
The cyclic movement of nutrition materials is called nutrition flow
...
Energy flow in the ecosystem
The sun is the main source of energy in any ecosystem
...
This energy,
stored in plants, reaches different tropic levels through different kinds of food chain
...
The herbivorous animals, consumers of first level, maintain their life by eating leaves,
stems, flowers, fruits, seeds or roots of green plants
...
The carnivorous
animals, who live by eating the consumers of first level (herbivorous animals) are the
Biology
185
consumers of second level
...
Exactly, the chemical
energy from the consumers of second level reaches the consumers of third level in the
form of food
...
After death, procurement of energy is stopped in all the organisms
...
The energy
being stored in different inanimate substances of the environment becomes suitable for
the plants to use again
...
Some energy gets wasted in every level of all types of food chain
...
Again, the amount of nutrition that a consumer of second level obtains
from the herbivorous consumers does not even reach its own body, as some of the
energy is released in the inanimate environment
...
This is why if in an ecosystem the number of tropic
level is fewer, energy waste decreases accordingly
...
According to the principle, each of all these levels, primary producers,
primary consumers of first level, consumers of second level and the consumers of top
most level is a tropic level
...
The herbivorous consumers, consumers of first level are the representatives
of second tropic level
...
Some of the energy collected
from the sun in the producers or in the lowest tropic level of any food chain goes out in
every consecutive step as heat energy
...
The amount
of energy is more reduced reaching the top most tropic level
...
The structure of tropic levels in an ecosystem
is shown with the structure of a pyramid
...
The amount of energy is much higher in the level of producers than that
of the next tropic levels
...
This
is why the producers and the top most consumers are placed on the base and at the top of
the pyramid respectively
...
The flow of energy is always unidirectional
...
About 80% to 90% energy is reduced in every stage
...
The more a food chain is
long the more energy would be reduced in higher tropic level and at one stage there
would be remain no energy
...
Here
is the assemblage of many types of organisms and innumerable kinds of inanimate
substances
...
Until now, it has become possible to describe and identify 15 lakhs
species
...
For instance, jackfruit is a
species, and it is possible to separate it from other species by its special characters
...
Again, human being is a species
...
They are all not exactly the
same and are different from each other in some characters
...
Briefly, to say it can be said that biodiversity is
the abundance and variability among organisms existing on the earth
...
Such as (1) species diversity, (2)
genetic diversity and (3) ecosystem diversity
...
Such as, a deer is distinct from a tiger in size, habit, ferocity, number, mode
Biology
187
of multiplication etc
...
Genetic diversity: Differences in many issues are found in the members of the same
species
...
These differences
emerge because of the little diversity in composition of their genes
...
There is a gene
for every character
...
Through
this process, the diversity introduced with the organisms is called genetic diversity
...
These changes
are, of course, slow and steady
...
As a result the biodiversity, developed there, is called ecosystem
diversity
...
In the ecosystem of forest, grassland, lake,
river, water reservoir, hill, sea, desert etc, the living communities are developed with
their own distinct characters
...
For
maintaining the balance in the environment, this complex relationship has been
developed
...
Only the extinction of a species in an environment may cause a large
catastrophe
...
The organisms and animals, which were once considered unnecessary and undesired,
with the passage of time, it has been found that these organisms are continuously playing
their necessary roles for the conservation of the environment
...
They could
purify the water of the total locality by only three days
...
As a result, the remaining oysters cannot purify the water of that total
locality even by a year
...
A
mature toad in a day can eat the amount of worms and insects equal to its body weight
...
For the use of
different pesticides, toads are being killed
...
Among them, the number of the pests, which cause harm to humans and cultivated
harvest, is high
...
We know that
owl, eagle, vulture, and raptor are predatory birds
...
If a pair of rats, living at a house of a human without any trouble
188
Biology
could reproduce freely, the number of rat would be 880 at the end of a year
...
If vultures, raptors and crows would not clear the dead and
decaying organic matters, the world would be covered with them
...
If any organism is extinct from the
environment, the stability of an ecosystem is destroyed
...
Interaction and interdependence among different organisms and the balance of
environment
Green plants are generally called self-dependent because they are autotrophic
...
Plants, birds and animals, worms and insects and other
organisms influence each other
...
For photosynthesis the green plants use the
carbon dioxide that is released by animals during respiration
...
Moreover, bacteria, fungi and different
microorganisms in different ways affect plants, animals and worms and insects
...
So, in the living world existing organic relationships between plants
and animals can be designated with the term symbiosis
...
It has also been clear from
the discussion made above that the organisms, participating in interactions, are
interdependent and none is self-sustaining
...
Such as,
(a) by positive interaction and
(b) By negative interaction
...
In this symbiotic organisms, one or both may be
benefited
...
Mutualism: The relationship is mutualism when in
the association both the organisms become benefited
...
fly around from
flower to flower to attain the nectar and as a result the
pollination is accomplished
...
This way seeds are transferred and the
distribution of plants is done
...
The association of an algae and a fungus forms lichen
...
On the other
side, the algae by its chlorophyll produce food carbohydrates for itself and for the
fungus
...
They supply this fixed nitrogen to the host leguminous
plant and in return collect their food carbohydrates from it
...
Though the other associate
is not benefited, it does not lose anything
...
This way it collects sufficient amount of light
by spreading on other plant
...
Epiphytic plants collect
food from the air but do not do any harm to the plant providing shelter
...
Negative interaction: In this case the relationship is detrimental to one or to the both
...
A dodder with the help
of the absorbing structure hosteria collects food from the plant, which has provided it
with shelter
...
It lays its egg in the nest of a
crow, and the crow hatches its egg and once the embryo of cuckoo comes out of the egg
being sufficiently grown up by breaking the shell of the egg
...
In this competition the stronger one survives and the weaker one is
abandoned
...
It becomes clear from the discussion made above
those actions and reactions are continuously
occurring in between the organisms existing in an
environment and every component is interrelated
to each other
...
This
way they are maintaining the balance of the
environment
...
There are innumerable number of organisms on
the earth and for their survival there are different substances such as soil, water and air
etc
...
In this catastrophic situation if people do not become
much conscious of it, catastrophe will turn into a more serious state
...
In the realm of nature all the organisms and the inanimate
substances are each other tied closer
...
and the existence and well
being of human race are based on it
...
So, biodiversity will be sustained if the environment is
well conserved
...
will be continuously fulfilled
without any disruption
...
The temperature is raised
for the increasing amount of greenhouse gases (CO2, CO4, N2O etc
...
For the enhanced greenhouse effect sea level will rise and
consequently, vast coastal areas will be inundated, weather will be changed, forest will
be damaged, crops will be destroyed by different pests and the severity of storm and
tornado will raise
...
This is why from now on all the best measures should
be taken to conserve the environment
...
The whole world has to come forward for the maintenance of a healthy
Biology
191
environment
...
Plantation should not be limited only in a weekly or monthly programme
...
Before setting any industry and mills in
any locality, their adverse effects on the environment should be first taken into
consideration and safe disposal of industrial waste should also be ensure
...
Massive plantation should be carried out side by side with the
rapid urbanisation
...
Excessive use
of chemical fertilizers and pesticides damage the normal quality of soil and degrades
beneficial microorganisms, terrestrial worms and insects, aquatic and terrestrial
ecosystems
...
Use of chemical fertilizers
and pesticides should be minimized
...
Population should be controlled and communities
of well-educated people should be developed
...
Mass media
should play a prime role in this regard
...
To control the soil
erosion in coastal areas, massive plantation must be accomplished
...
Normal flow of
water should be conserved by dredging river and water bodies
...
It is essential to conserve the biodiversity for the sustenance of healthy environment and
with this view all the plant and animal species, which are on the verge of extinciont
from nature, should be conserved by special processes
...
International and national principles
and guidelines should strictly be followed
...
Exercise
Short answer question
1
...
2
...
What is a parasitic food chain?
4
...
What is mutualism?
Essay type question
1
...
Explain it
...
Which one is a parasitic food chain?
a
...
saprophyte decomposer amoeba
c
...
green plants bird
fox
2
...
one is benefited from the associates
...
though none of the associates is benefited but none is also harmed
...
both of the associates become benefited
...
i
b
...
ii & iii
d
...
1
b
...
3
d
...
In the light of the stem which one is the consumer of second level?
a
...
snail
c
...
grasshopper
Creative question
1
...
What are decomposers?
b
...
c
...
Analyse what the consequences will be occurred in the ecosystem if the bird in
the food chain mentioned above is extinct
...
a
...
c
...
What is biodiversity?
Write in detail what you understand by commensalisms
...
Analyse the impacts of the reactions caused by the process mentioned in the diagram
above
...
It has opened new horizons in solving
many real problems in different branches of science
...
In this
chapter, we will try to know the facts about this technology briefly
...
x
Explain tissue culture
...
x
Explain the objectives of genetic engineering
...
x
Describe the use of genetic engineering in producing insulin and hormones
...
x
Describe the use of biotechnology in curing diseases of animals
...
x
Understand the contribution of biotechnology in our everyday life
...
The word
biology means special knowledge about organisms and technology means a manner of
accomplishing a task specially using technical processes, methods or knowledge
...
In 1919 Hungarian
engineer Karl Ereky first coined the word biotechnology
...
In the advancement of science, biotechnology is not only a new addition
...
Man acquired the knowledge
of fermentation and brewing about 8000 years ago
...
With the continuity of the invention of
double helix model of DNA by Watson and Crick in 1953, today’s biotechnology has
emerged
...
In order to live well in a healthy and beautiful environment in the present world by
ignoring the huge pressure of increasing population, there is no alternative to
biotechnology
...
By using this technology amount of protein has been increased a lot more than
the past
...
Through tissue
culture the species of potato, tobacco and banana resistant to virus have been invented
...
Microbes such as bacteria, blue green algae and fungus are being used in
producing compost
...
An eon making invention is the insulin made by adding human insulin gene to bacteria
plasmid and entering them into e-coli bacteria
...
But this protein is
produced so little in human body that it cannot prevent cancer
...
With the help of this technology, interferon is now being produced commercially and its
price is lower than the past
...
But through this technology, its production has
quite gone up
...
If error is found in
any of these cells, disease can attack human body
...
It is hoped that these disorders will be removed through this
technology
...
Biology
195
Some microbes improve the colour, flavour, nutrition of different crops through their
effect on them
...
Besides there are certain microbes turn certain carbohydrates into alcohol
through fermentation
...
For enhancing the quantity and quality of
different medicines, this technology is applied
...
Daily waste matters, industrial discharges are being degraded by microbes for the
improvement of environment
...
If bio diversity of any area is
destroyed, it has a serious bad effect on the environment of that area
...
For example efforts are being made for
rapid propagation of almost extinct plants through tissue culture in order to maintain
ecological balance
...
For example different bacteria are being used for
extracting copper and uranium
...
At present for controlling
different pests and insecticides, organic pest control system is being used instead of
different chemicals
...
Tissue culture: Generally, one or a group of cells of the same type is called tissue
...
Tissue culture is comparatively a new branch of botany
...
All the elements for the nutrition and growth
of tissue are supplied with the sterilized medium
...
Steps of tissue culture
1
...
196
Biology
2
...
3
...
Later in an
autoclave machine, keeping it at the temperature of 1210C under 15-lb/sq
...
After the turning of the medium into a cold and
semi-solid state, explants are inoculated on it
...
In this stage, the tissue placed on
the medium through repeated cell division turns directly into a plantlet or callus or a
cluster of cells without differentiation
...
Transfer in root developing medium: If no root is developed in the plantlets by this
time, then after attaining a definite height, shoots are cut and again placed in the root
developing medium
...
Transfer to natural environment or to field level: After washing with water and
putting them outside the room on the tubs, the plantlets are allowed to adapt with the
external environment
...
Use of tissue culture: By utilizing the tissue culture, now a days in the reproduction of
plants and in field of developing new variety, much achievement has been obtained and
new horizons have evolved with the vast hopes
...
Easily disease
free and especially free from viruses, plantlets can be produced
...
As the facility of producing
plantlets in a short period of time in a very conspicuous place, sufficient number of
plantlets can be produced and the problem of storing of seeds can be avoided
...
Tissue culture
technology is well accredited for the production and conservation of the species about to
be extinct
...
The rapid multiplication of the plants, which do not reproduce
through sexual reproduction or of which rate of natural reproduction is low, can be done
by culturing their embryo
...
French scientist George Morel (1964) proved that it is
possible to obtain 40 thousand plantlets from a meristem of the orchid plant named
Cymbidium in a year
...
In Thailand 50 million plantlets, which are mostly orchids, are
produced through tissue culture method in a year
...
earn every year crores of foreign currency
...
Nowadays, it has become a regular practice to make some
plants free from viral diseases by culturing their meristems, such as potato tubers
...
It is possible to
Biology
197
obtain 88 crores of plantlets of Garland of Chrysanthemum from a vegetative part of it
through tissue culture
...
Commercially the perfume atar is being produced from the suspension of Jasminum
using this technology in many different countries
...
a kind of oil from sperm whale is required
...
In an alternative way, this oil is being derived only
from a plant named jojoba but this plant does not grow anywhere except in a special
desert environment (such as, in Arizona, California), and their reproduction is also time
consuming
...
In
Bangladesh by this time much more successes have been made through tissue culture,
such as it has become possible to produce the plantlets of different orchids grown in the
country and in other countries
...
Garland chrysanthemum, gladiolus, lily,
garden carnation etc
...
Cadamba, Jarul, epil
epil, bakul, teak, nim etc
...
Plantlets of
different types of pulses, groundnut, jute have
also been produced
...
Genetic engineering
With the view of changing the body of
organism in quality by special technique of
biotechnology, changing of gene particle in the
centre of a cell is called genetic engineering
...
Genetic engineering is also
called recombinant DNA technology
...
The organism with the
new characters is called GMO (genetically
modified organism) or GE (genetically
engineered) or transgenic
...
(b) Selection of a carrier so that the transfer of desired segment of DNA becomes
possible
...
198
Biology
(d) Selection of DNA ligase enzyme to join the segments of DNA chopped
...
(f) Evaluation of the expression of recombinant DNA prepared with the desired DNA
segment
...
Genetic engineering is more effective for the development of new crops in comparison
with traditional ways of reproduction because transfer of gene is similar or limited to the
nearest species through traditional reproduction
...
Moreover, it
requires long time to achieve the desired result through traditional way of reproduction
...
In case of traditional reproduction, unexpected genes may
be transferred with the desired gene and the transfer of desired gene also remains
uncertain
...
Traditional reproduction is not controlled by
any rules and methods of bio-safety, but in case of genetic engineering it is controlled by
internationally accredited rules and methods of bio-safety
...
Genetic engineering in developing crops: Genetic engineering or recombinant DNA
technology is the most modern biotechnology
...
By this time notable successes have already been achieved
through this technology
...
These fruits are resistant to the harmful insects
under Lepidoptera and Coleoptera orders
...
Using this technology, virus resistant varieties of crop have been developed, for instance
by transferring gene, tomato mosaic virus (ToMV), tobacco mosaic virus (TMV) and
tobacco mild green virus (TMGMV) resistant varieties of crop have been developed
...
The
research is being carried out for the development of late blight resistant variety of potato
by transferring late blight fungus resistant gene
...
Scientists have become able to develop herbicides tolerant variety of tomato by
transferring herbicides tolerant genes into the tomato from a kind of bacteria
...
have been
produced
...
Nowadays, with no trouble this type of transgenic plants is commercially available
...
Through genetic change, nutrition value of some crops has been improved
...
e
...
Taking efforts to add iron
in rice is being continued
...
In animals: In livestock, for example transfer of protein C gene has been done to
increase protein in cow-milk though still it is in research level
...
To improve the amount and quality of
sheep’s fur, 2 bacterial genes, such as CysE and CysM have been transferred to the
genome of sheep
...
From genetically modified E
...
Human growth hormone and components of the stimulant for
accelerated growth of granulocytes macrophage colony are being produced from
genetically modified E
...
In improvement of fishing: The areas of petroleum industry and refinery and coal
mining are free from pollution because this technology is being used with a view to
making the environmental management easy and fast, such as management of industrial
wastes and sewage
...
M
...
Chakraborty, by performing research on genetic
engineering, has developed a variety of Pseudomonas bacteria which is able to
disintegrate immediately oil and hydrocarbon in any environment
...
Work-2: Prepare a report on the scope of educating biotechnology and genetic
engineering in Bangladesh, and submit it to your teacher
...
How is culture medium prepared?
2
...
What is explant?
4
...
What is transgenic?
200
Biology
Essay type question
1
...
2
...
Multiple choice question
1
...
ligase
b
...
lactase
d
...
Biotechnology is applied to
...
fermentation
ii
...
develop transgenic organism
Which one of the following is correct?
a
...
i & iii
c
...
i, ii & iii
Pay heed to the following stem and answer the question 3 and 4
...
To
produce the plantlets of exact characters, he brought some lateral buds of the plant,
and produced them in his university lab of Botany department
...
What is the process that Imtiaz followed in the lab?
a
...
application of hormone
c
...
tissue culture
3
...
preparation of culture media
inoculation of explant development of plantlets
development of roots transfer to natural environment
b
...
selection of mother plant
preparation of culture media inoculation of explant
development of plantlets transfer to natural environment
d
...
Hayder, the lemon plants are dying
rapidly being diseased though the lemon harvest is high
...
From these two varieties of lemon, he developed a new, high yielding and disease
resistant variety
...
1
...
What is GMO?
3
...
Hayder for the development of lemon variety
...
Explain the causes of developing plantlets through the special process by Dr
...
The End
Title: Easy Biology For Class 9-10
Description: Reading this book you can easily learn biology.
Description: Reading this book you can easily learn biology.