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A balanced diet
A balanced diet supplies al essential needs
...
Energy requirements depend on age, sex,
pregnancy and activity levels
...
Take explants
coronary heart disease
2
...
Grow in vitro (petri dishes containing
nutrient medium)
4
...
Species becomes more adapted for survival
Genetic diagrams
Genotype- the alleles you have
Phenotype- the characteristics the alleles produce
1
...

3
...


•

•
•
•
•

Indicators:
iodine- tests for starch (starts orange, turns blue/black
if present)
Benedict's solution- tests for glucose

DNA, genes and chromosomes
• Genetic material is found in the nucleus
• A gene is a short section of DNA that codes for
a particular protein
• Proteins control the processes in our body and
determine inherited characteristics
• Different versions of the same gene are called
alleles
• Chromosomes are long lengths of DNA coiled
up
• DNA is list of instructions
...

• It is held together by bases
...
It might stop the production of a
46
protein or mean a different protein is produced
instead, leading to new characteristics
...
The resistant gene is passed on so
the antibiotic is no longer effective
...
This becomes
a vector (something that
transfers DNA to a cell)
Mix together and join using
ligase enzyme to make
recombinant DNA
...
g
...
Sewage also contains lots of phosphates
from detergents and nitrates from urine and faeces
...
Promotes excessive growth of algae which form a
layer on pond
2
...
Bacteria decompose dead algae and use up oxygen Auxin is the plant hormone that controls growth in
4
...
It responds to light (phototropism)
and gravity (geotropism)
Artificial plant hormones
Weed killers
Rooting hormones
Cause weeds to grow Cuttings are taken from
very quickly, which
plant, which are then dipped
they cannot sustain so into rooting powers
...

hormone in the power
causes cells in cuttings to
develop into roots

Hormone

source

Role

effect

ADH

Pituitary gland

Control water
content

Increased permeability
of kidneys to water

Adrenaline

Adrenal gland

Fight or flight
response

Increases heart tare,
blood flow to muscles
and blood sugar levels

Blood sugar
levels

Stimulates liver to turn
glucose into glycogen
for storage

Insulin

Pancreas

Hormones are chemical
messengers carried in the blood
plasma, produced in glands, have
a slow and long lasting effect

Coordination and response

A nerve
A neurone

Reflexes are quick because no
information has to travel to
the brain for reflex to occur
...


Information travels along neurones as electrical impulses, and cross small gaps
called synapses
...
We have them so each neurone can
make lots of connections with other neurones
...

If the water concentration falls,
then more ADH is produced
...
This
means that a small volume of
very concentrated urine is
produced
...

If the water concentration rises,
then less ADH is produced
...
This means
that a large volume of very
dilute urine is produced
...


Thermoregulation
The hypothalamus is the part of the brain which monitors the body's
temperature
...

Too cold:
• No sweat
• Hair erector muscles contract to
trap a layer of hair
• Vasoconstriction (blood vessels are
more narrow and less heat is lost
through skin)
• shivering (muscles contract and
relax using energy from respiration)

Too hot:
• Sweat evaporates removing
heat and leaving the skin cooler
• Hairs lie flat
• Vasodilation (vessels come
nearer to surface so more heat
is lost)

The eye

Enzymes
Enzymes are biological catalysts- they increase the speed of
a reaction without being used up or destroyed
...


PROS

CONS

Only catalyse the reaction needed
(they are specific)

People can develop
allergies

Mean a lower temp and pressure
are required so is cheaper

Uses of enzymes
• In biological detergents (protease and lipase)
...
More effective at lower temps
...

Proteins are made of carbon, • Protease- produced in stomach, pancreas
Stages of digestion
and small intestine
nitrogen, hydrogen and oxygen
...
Ingestion (putting food into mouth)
Proteins amino acids
2
...
Absorption (nutrients move through intestine walls to
Lipids glycerol and fatty acids
blood)
White blood cells
4
...
Egestion (undigested food removed via anus)
Engulf pathogens,
Produce antibodies,
Note: egestion is the removal of waste products from
non-specific
specific, mark antigens
chemical reactions such as sweat and carbon dioxide
for destruction, stay in
Red blood cells
body as memory cells
• Bio-concave
• Large SA
• No nucleus
• Contain haemoglobin

• Oestrogen- causes lining to thicken and
grow, stimulates release of ovum, female
secondary sex characteristics
(wider hips, breasts, periods, pubic hair)
• Progesterone- maintains uterus lining
• Testosterone- male secondary sex
characteristics
(deeper voice, facial and pubic hair, voice
breaks, increased muscle growth)

Minerals for healthy growth:
Nitrates- amino acids and proteins for cell
growth (stunted growth)
Phosphates- DNA and cell membranes for
respiration and cell growth (purple leaves)
Potassium- help enzymes needed for
photosynthesis and respiration (poor fruit
and flower growth)
Magnesium- chlorophyll for
photosynthesis (yellow leaves)
photosynthesis
Transpiration is the loss of water from the plant
...

from roots to leaves, made of dead
• It turns light energy into chemical energy
...

Phloem- carries food substances made
Factors affecting rate of
Things that
in leaves to rest of plant for growth or
stop
photosynthesis:
storage
photosynthesis
1
...
Co2 concentration- more
any faster
Population: all organisms of the same species
co2=more photosynthesis
are limiting
Community: all the different species in a
3
...
g
...
Not
always pyramid
...
ALWAYS
PYRAMID SHAPED
...
Nucleus from male gamete
travels down to female gamete in ovary
...

Germination- when seeds start to grow
...
When leaves appear plant can get own energy from
photosynthesis instead of using food store
...
Sterilise the equipment to kill
• Sugars in solution
unwanted microorganisms
(food)
2
...
Add lactobacillus bacteria to milk
and incubate in a fermenter at 40’C
respiration
Fermenter is full of culture
medium so bacteria can
grow and reproduce
...
g
...
Bacteria ferment lactose sugar into
to lactic acid
5
...
Get the barely out of the grain
2
...
Leave to dry in a kiln (malting)
4
...
Sieve the mixture and add hops to give
flavour
6
...
Rising alcohol levels start to kill the
yeast and fermentation slows
8
...
Pasteurise the beer to kill any remaining
yeast and completely stop fermentation

Mitosis
Chromosomes
copied

Animal cell

Two daughter
cells (identical to
parent)

plant cell

Meiosis
Chromosomes
copied
Divides twice
Four haploid cells
(gametes),
23 single
chromosomes
Lets blood of embryo
and mother get close to
allow exchange of food,
oxygen and waste

fungi cell

bacteria cell

Amnion membrane
forms and protects baby
from knocks and bumps

Reproductive systems
Produces egg
and sex
hormones

(sperm duct)
Carries sperm
from testes to
urethra

Carries sperm
through penis
during ejaculation

Where sperm are
made

Uterus lining (good blood
supply for embryo
implantation)

Organ where
embryo grows

Where the sperm
are deposited

Carries
ovum
from
ovary to
uterus

Fish farming
Fish are farmed in fish farms because they are a good
source of protein
...

Variables:
• Water quality-filtered and cleaned regularly
• Competition- protected from predators by cages
and nets
...

• Feeding quality and frequency- high quality
feedstock to maximise energy transfer, little and
often to prevent overfeeding and discourage
competition

Increasing crop yield
Maximise photosynthesis:
• Enough co2
• Light intensity
• temperature
1
...

2
...
Pest controls:
• chemical control- Pesticides
• biological control- Encouraging wild
organisms or adding new ones e
...

predators (e
...
ladybirds), parasites (e
...

flies laying egg on slugs), disease
causing (e
...
bacteria kill caterpillars)

Pros

cons

Diet can be
monitored

Can cause eutrophication from
food pellets and animal waste

Yield and quality of
fish is improved

May spread disease as closer
together

Biological control

pesticides

Protection against
predators

Pesticides may be toxic to nonharmful species

Longer lasting and more
sustainable, but is a slow
process

effective

Often specific (will only eat the
thing intended to eat)

May affect other
animals in food
chain

Protection against predators

Ecosystem will be
broken up

Doesn’t completely destroy a
pest

Humans may get
diseases

Indicators:

EXPERIMENTS
Potential hazards

precaution

Microorganisms

Some bacteria
make us ill

Chemicals

Sulphuric acid can
burn skin, alcohols
can catch fire easily

Fire

Unattended
Bunsen burners

Electricity

Faulty electrical
equipment could
give a shock

•
•
•
•
•

Wear gloves
Tie hair back
Wear goggles
Wash hands
Use fire proof
matt
• No water
near
electricity

Measuring osmosis (living)
1
...
Put some in sugar solution
and some in pure water
3
...
Leave pondweed to
photosynthesise for a 2
...
Tie wire around one end of viscous tubing,
put a glass tube in other end and tie
2
...
Measure where liquid is up to
4
...
Water will be drawn in and liquid will
move up tube
6
...
Use scalpel to cut out agar
cubes (containing
phenolphthalein indicator
and sodium hydroxide)
2
...
Repeat with different sized
cubes

The rate at which
pondweed produces
oxygen corresponds to the
rate of photosynthesis
...


high

Hydrogen carbonate- shows change in
CO2 concentration

Measuring diffusion

Measuring light intensity and photosynthesis

low

Gas exchange in plants
1
...
Use hydrogen
leaf and foil (no sunlight),
carbonate indicator
leaf in gauze (a little light)
to measure change in
and a leaf in sunlight (lots of co2 concentration
light)

control

More
Respiration and photosynthesis
No
than
photosynthesis photosynthesis
respiration

Calorimetry- measuring the energy in food
Increasing accuracy:
Insulate boiling
tube
• Hold food nearer
tube
• Make sure the
food sample is
completely burnt
out

thermometer •

25cm’ water
Mounted needle
with food sample
heat

Heat is lost to
surrounding air
and to glass tube

1
...
Measure temp of water
3
...
Keep relighting until it no longer
learns
5
...
2
Energy per gram= energy in food
mass of food

Measuring transpiration (potometer)

Demonstrating CO2 production
Use hydrogen carbonate solution to show that living
organisms produce CO2 as they respire
1
...
Boil a second bunch so that
they die
Boiled Germinated
beans
beans
3
...
Seal with rubber bung and
leave for set time period
CO2 present
(respiration)

Ecosystem investigations
Estimating population size:
1
...
Count all the organisms within
the quadrat
3
...
Repeat at another area to compare population
sizes, or continue at more random places to calculate
an average

Measuring distribution:

1
...
Collect data along the line using quadrats next
to each other

Heat produced in respiration
thermometer
Cotton wool
Vacuum flask

Measure distance moved by air bubbletranspiration means water is lost through the leaves
so water is pulled upwards
Making it more accurate:
• Cut stem at a slant to increase water uptake
• Use a bung to prevent water evaporation
Measuring transpiration (using a balance)
Measure the change in weight
Making it more accurate:
• Use a layer of oil to stop evaporation

balance

Changing variables:
•
Light- use a lamp or put in cupboard
•
Temperature- use a heater
•
Humidity- spray water into air
•
Wind speed- use a fan

1
...
Add each set to
Dead boiled beans
vacuum flask, but
make sure there
is some air so
beans can respire
aerobically
3
...
Record the temp
of each flask for a
Soaked
month
germinated
beans

Temperature and enzyme activity

Respiration rate of yeast with enzymes

How fast a product appears- the breakdown of hydrogen
peroxide using catalase
H2O2 H2O + O2
1
...


3
...
g
...

Put starch solution containing amylase in a
2
...

4
...

2
...

4
...


Kill leaf by dunking in boiling water to stop any chemical
reactions happening
Heat in water bath with ethanol to get rid of chlorophyll
Rinse leaf in cold water
Add iodine solution
If starch is present leaf will turn blue/black
...
Mix together sugar, yeast
and distilled water
2
...
Count how many bubbles
are produced in a given
period of time
4
...

2
...


Put a plant in a cupboard
to grow without light
Take leaf from plant and
test for starch
Will no change colour as no
starch can be made as light
is needed for
photosynthesis

The chlorophyll test
Use variegated leaves (only the
green parts contain chlorophyll)
1
...

Test for starch using iodine
solution
3
...

Leave plant in
sealed bell jar with
soda lime and
sunlight
2
...

Will not change
colour as CO2 is
needed for
photosynthesis



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