Notesale: Turn your study into money

Document Preview

Extracts from the notes are below, to see the PDF you'll receive please use the links above

---

SPECIATION
EXAMPLES OF SPECIATION

CONCEPT OF SPECIATION
SPECIES




Group of organisms with structure, function,
and behavior
Distinct, identifiable types of organisms
Morphology, physiology, biochemistry and DNA
similar

EMST MAYER BIOLOGICAL SPECIES CONCEPT
o Group of populations whose members have the
potential to interbreed in nature and produce a
viable, fertile offspring — but do not produce
viable, fertile offspring with members of other
such groups
o “Reproductive Isolation”
SPECIATION
Emergence species by of new splitting one
lineage into two
o The new species will
share some of the
characteristics from
its ancestor
o The demands of a
different
environment or the
characteristics of
the members of the
new group will
differentiate the
new species from their ancestors






SPECIES OF CATS AND DOGS, THEY HAVE
DIFFERENT BREEDS OR TYPES
MULE - MARE (female horse + make donkey)
Liger - Mare (female tiger + male lion
For humans there are different race that makes
each human different from
each other

TYPES OF SPECIATION
ALLOPATRIC SPECIATION
 “Other country” speciation
 Population is divided into
geographically isolated
subpopulations

o

PARAPATRIC SPECIATION
 Speciation with geographic overlap
Hybrid zone - where members partial region of different
species meet and mate
 different habitats influence the development of
different species
 Instead of being separated by a physical barrier,
the species are
separated by
differences in the
same
environment
...
Chromosomal mutation
b
...
Habitat differentiation

DIFFERENCES OF TYPES OF SPECIATION

REPRODUCTIVE ISOLATION AND ITS 2
TYPES

PREZYGOTIC BARRIER


Prevents individuals of different species from
mating successfully

TYPES OF PREZYGOTIC BARRIER
1
...
Temporal Isolation
o Different species breed on different
time/season
o Species that breed during different
times of the day, different seasons, or
different years cannot mix their
gametes
...
Behavioral Isolation
o Different courtship display
o An example of this is how birds shows
courtship with other birds
4
...
Habitat Isolation
o Two species that occupy different
habitats within the same area may
encounter each other rarely, if at all
...
Reduced Hybrid Viability
o The genes of different parent species
may interact in ways that impair the
hybrid’s development or survival in its
environment

2
...
If the chromosomes of the
two parent species differ in number or
structure, meiosis in the hybrids may
fail to produce normal gametes
...
g
...


3
...


THE PLANT TISSUES AND
BODY
THE PLANT BODY CONSITS OF SHOOT SYSTEM AND
ROOT SYSTEM
SHOOT SYSTEM
 Photosynthesis
 Reproduction
 Storage
 Transport
 Hormones
ROOT SYSTEM
 Anchorage
 Absorption
 Storage
 Transport
 Hormones

PLANT TISSUE
TISSUE


a group of cells that are similar in structure and
organization and work together to perform a
particular function
Plant Tissues
o are specialized for functions: absorption,
transport, storage, photosynthesis and
reproduction
WHAT IS A PLANT TISSUE?
 A tissue is an organization of cells that work
together as a functional unit
...

 Xylem and phloem are complex tissues; they are
composed of a number of different cell types
...

 There are three plant tissue systems: vascular,
dermal, and ground
...
DERMAL TISSUE
o Outer covering or "skin" of the plant
2
...
xylem and phloem)
3
...


XYLEM AND PHLOEM
1
...


2
...


MERISTEMATIC TISSUE




A tissue in plant that divide continuously to
bring plant growth (continuous cell division and
growth)
are either undifferentiated or incompletely
differentiated

FUNCTIONS OF MERISTEMATIC TISSUE
 Meristematic tissues can divide; hence they
continuously produce new cells which keep
differentiating to form specialized cells of plant
...

 The cells in the lateral region bring about an
increase in the girth (thickness) of the plant

3
...
Main function- to increase the
thickness of stems & roots
...
APICAL MERISTEM
o Present at the growing tips of stems &
roots
...

o Found at the apices of the stem and
roots

GROUND TISSUE

2
...
main function- for the
longitudinal
growth of
plants
...

cells may be dead or alive, thin walled or thick
walled

SIMPLE TISSUES
 group of cells which are alike in origin, form and
function
...
PARENCHYNA
o oval, spherical or polygonal in shape
...

o Widely
distributed
in the stem,
root, leaves,
flowers and
fruits
FUNCTION OF PARENCHYNA
A
...
maintaining the turgidity of cells
...
gives mechanical strength to the stems of
herbaceous plants
...
allows transport of water and mineral salts in
plants due to being thin walled
2
...

o The corners
are thickened
due to extra
deposition of
cellulose and
pectin
...

They often contain chloroplasts
...
Their primary function is to give mechanical
support to herbaceous plants
B
...
SCLERENCHYMA
o Sclerenchyma cells when matured are
dead and without any protoplasm
...

o They have
thick walls
due to
deposition of
a waterproof
material
called lignin
...

FUNCTION OF SCLERENCHYMA
A
...

B
...
Fibers being strong and flexible, they are being
used in manufacturing ropes and textiles

COMPLEX TISSUE
 comprised of different kinds of cells, all adapted
to perform a common function and work
together as a single unit
 xylem and phloem are two main complex tissue
...
XYLEM
o

meant for upward conduction of water
and minerals from roots to aerial parts
of plan
o Transports
water
o Made up of
long hollow
tubes formed
by non-living
cell walls
called
Tracheids or
Vessel
elements
o Non-living matter was once living (cells
die, leaving cell walls as tubes
PARTS OF XYLEM

FUNCTION OF XYLEM
A
...

B
...
helps in lateral conduction of water and storage
of metabolic wastes
...
PHOLEM
o that aids in the translocation of food
from leaves to other parts of a plant
...

Flowers, fruits and
etc
...
The main function of phloem is translocation of
prepared food material from leaves to various
parts of the plant for storage and growth
...

 Epidermal cells are typically small and can
differentiate into: stomata, trichomes, and root
hairs
...
STOMATA
o Pores that enable gas exchange
2
...
ROOT HAIRS
o Increase the root surface area



---