2. Diet and Exercise
• Healthy diet = Balanced Diet
• Exercise increases the amount of energy used
by the body and decreases the amount of
stored fat
• Inherited factors can affect your metabolic
rate and your blood cholesterol levels.
3. Pathogens
• Bacteria are 100 times smaller than body cells, and
they reproduce quickly
• Some Bacteria can damage your cells or produce
toxins
• Virus’ are 100 times smaller than bacteria
• They invade the body cells and replicate inside the
cell until the cell bursts.
4. White Blood Cells
White blood cells travel in the blood. If they come
across an invading microbe they act in theses ways :
• Engulf these microbes and digest them
• Produce antibodies
• Produce antitoxins
6. Producing Antibodies
• Every pathogen has an antigen on its surface, when white
blood cells come across one they don’t know they start
producing proteins to kill them. These are called antibodies
White blood cell It produces an New microbes attacked
detects microbe antibodies by new antibodies
7. Producing antitoxins
• These are produced by the white blood cells
to counteract the toxins made by the invading
bacteria
8. Vaccination
Pros Cons
Help control infectious diseases, to Vaccines don’t always work, so they
stop death in that country wouldn’t give immunity
Epidemics are less likely to spread People can have reactions to the
even if only a percentage of the vaccines such as swelling or even
population is vaccinated seizures. However these are
uncommon
9. Sense organs
• Sense organs detect stimuli
• They all contains different receptors i.e eyes
have light receptors. This means it is sensitive
to light
• They are: eyes; nose; ears; mouth; tongue and
skin
10. CNS
• The central nervous system is where the
information from the sense organs is sent, so
reflexes and actions can be coordinated.
• It consists of the brain , spine and the neurone
path way
11. Neurones
Sensory- nerve cells that carry electrical signals from
the receptors to the CNS
Relay- nerve cells that carry electrical signals from the
sensory neurons to the motor neurons
Motor- nerve cells that carry electrical signals from the
CNS to the effecter muscle/gland
Receptor CNS CNS Effecter
Sensory Relay Motor
12. Hormones and Nerves
Nerves Hormones
Very FAST SLOWER action
Act for a SHORT time Act for a LONG time
Act in a PRECISE area Act in a GENERAL way
13. Menstrual Cycle
STAGE 1: This is the break
down of the uterus lining
STAGE 4: The wall is
maintained for these
days. If no fertilised STAGE 2: The lining of
egg implants then the the uterus builds up
cycle starts again
STAGE 3: An egg is released on
day 14. These are the most
fertile days
14. Hormones
FSH- Produced by the pituitary gland
- Causes eggs to mature in the ovaries
- Stimulates the ovaries to produce oestrogen
Oestrogen- Produced in the ovaries
- Causes pituitary to produce LH
- Inhibits the release of FSH
LH- Produced in the pituitary gland
- Stimulates the release of an egg at the middle of the
menstrual cycle
15. Plant Hormones
• Auxin is plant hormone that controls growth
near the tips of the shoots and the roots
• Phototropic, Hydrotropic, or Geotropic
• If auxin move backwards it will stimulate cell
elongation
• If the tip is removed, no auxin is available so
may stop growing
17. Testing medicines
1. Drug tested on human cells/tissues
2. Drug tested on live animals
3. Healthy human volunteers (small)
4. People suffering (includes placebo)
5. Ongoing reporting from doctors
18. Recreational Drugs
• Hard drugs- are seriously addictive and
normally more harmful
• People use them for stress relief, enjoyment,
peer pressure or relaxation
• Tobacco and Alcohol are both legal but they
both can cause serious damage to your body
23. Competition For survival
• Plants: light, space, water and minerals
• Animals: space(territory), food, water and
mates
24. Changes Causes by different factors
• Living things: Occurrence of diseases
Number of predators
Availability of food
Number of competitors
• Non- Living: Average Temp
Average Rainfall
Air/Water pollution
25. Population Increases
because of more food, this
means they will survive for
longer = more children
Population Decreases
because there is less food,
or more disease or more
pesticides. This means they
will die = less children
26. Indicators They measure environmental change
• Lichen- show levels of air pollution
• Mayfly (or other invertebre that need oxygenated
water) – they show levels of water pollution
• Rat-tailed maggots and sludgeworms – indicate high
level of water pollution
• Satellites- measure temp of the sea surface and
levels of snow fall
• Rain gauges- measure rainfall
• Automatic Weather Station- atmospheric temps
27. Pyramids of Biomass
• 100 flowers 10 rabbits 1 fox 500 fleas
• 15kg 10kg 6kg 1kg
Fleas
Fox
Rabbits
Flowers
28. Decay and Decomposers
• Plants take in carbon, oxygen, hydrogen and
nitrogen. They turn these elements into
complex compounds which they pass on
through the food chain
• Microorganism work best in warm, moist
conditions.
• The decomposers secrete enzymes to break
down the products
29. Carbon Cycle shows how carbon is recycled
CO2 in the air
Burning
Photosynthesis
Carbon compounds being decayed by microorganisms
Fossil Fuels
30. Variation
• Caused when two gametes meet and fuse.
The offspring will have a mix of the two DNA’s
causing Variation
• The environment can also cause variation, the
exposure to the sun causes a lot of variation
• Most characteristics are determined by the
mix of genetic and environmental variation
31. Genes Chromosomes and DNA
,
A human cell has 23
pairs of chromosomes
Most cells have a nucleus.
This contains genetic
information.
GENE- This is a long strand of DNA
Chromosomes
carry genes.
These control
development
of different Different versions of the same gene
characteristics give different characteristics
32. Sexual Reproduction
• Two organisms (father and mother) that have different
genetic information
• Parents produce gametes
• In humans a gamete has 23 chromosomes (half the
normal number)
• The gametes then fuse together, so the offspring
then has the normal number of chromosomes
• The offspring has mixture of characteristics
from mother and father
• This produces Variation
33. Asexual Reproduction
• An ordinary cell divides in two, this is a clone
because it has the same genetic information
35. Cloning Embryo transplants
1) Sperm and eggs cells are taken from a prize winning bull and cow
2) Embryo splits, divides and develops
3) These are implanted into surrogate cows
4) All offspring will be genetically identical
36. Adult cell cloning
Nucleus removed
Implanted Live
into a animal
surrogate
Electric mother.
shock
Cell removed
37. Issues of cloning
• There is reduced gene pool so one disease could
wipe out the population
• Animals might be less healthy because of the
cloning
• Worry about human cloning and the implications
However
• Could lead to greater understanding of
development of embryos, ageing and age-related
disorders
• Preserve endangered species
38. Genetic engineering
Example of using enzymes to ‘cut and paste’ genes
A useful gene is cut out of a
chromosome using enzymes. This is
put in to a bacteria. This then
reproduced. This is how they make
insulin
39. GM Crops
• Increase the yield of crops
• Crops made for people to add nutrients where
they are lacking
• Grown elsewhere without any problem
• Reduce biodiversity
• Some weeds could become resistant and
create a ‘superweed’ variety
