Out of balance diet results in
malnourishment (not starvation!)
Can result in obesity (causing
arthritis, type 2 diabetes, high
blood pressure, heart disease,
cancer)
Lack of food can result in
slow growth, fatigue, no
resistance to infection,
irregular periods, scurvy
Need exercise to burn energy
Health can be affected by inherited
factors-underactive thyroid gland
Metabolism rate of chemical reactions in the body
Drugs change body chemistry
Medicinal
Anitbiotics
Penicillin
Morphine
Testing medicines
1. Drugs are tested on tissues
2. Drug on mammals
3.Test on healthy volunteers
4. Testing on people with the illness- finding optimum dosage
5. Placebo tests
Thalidomide
Performance enhancing
Anabolic steroids and stimulants
All banned by sporting bodies
Recreational
Enjoyment, relaxation
Legal or illegal
Tobacco, alcohol, cannabis
Fighting disease
2 main types of
pathogens- Bacteria
and viruses
Bacteria- very small living cells
They either damage your cells
or produce toxins (poisons)
Viruses are not cells
They invade your cells, make
copies of themselves, then the
cell bursts releasing the viruses
Drugs and vaccinations
Vaccinations are a weak or
inactive form of the virus that
carry antigens, making your
body produce antibodies
Pros: Helped control lots of
infectious diseases, and epidemics
can be controlled and be less likely
tobreakout
Cons: They don't always work
and sometimes trigger bad
reactions, even though these are
rare
A lot of drugs only reduce the
symptoms of the disease, but
don't actually cure it.
However antibiotics such as
penicillin, prevent or kill the bacteria
inside your blood
Antibiotics do not destroy
viruses, as it would kill
your body's cells
Bacteria can become resistant to antibiotics, which is why you should
always complete a course of antibiotics, but do not take too much or too little
as it increases the bacteria's rate of mutation or reproducution
1st line of defence
Skin, hairs, tonsils,
2nd line of defence
Mucus, tears, non-specific
3rd line of defence
Antibodies, all specific, acquired with exposure to pathogens
Producing antibodies:
1. White blood cells engulf the pathogen
2. The white blood cells produce
proteins called antibodies to lock onto
and kill the invading cells.
3. Antitoxins are produced which
counteract toxins produced by the
invading bacteria
Hormones and the nervous system
Sense organs detect stimuli
using different receptors
Reflex actions
Stimulation of the pain receptor
The impulse travels along the relay neurone
Then along the motor neurone
Finally it moves to the effector
(Spinal cord)
The Menstrual Cycle
Day 1-4= Uterus lining breaks down
Day 4-14= Lining for the uterus builds up
and egg is released (Day 14)
Day 14-28= Lining is maintained
Cycle starts again
Hormones
FSH-Is produceD by the pituitary gland,
Causes egg maturation, Stimulates
ovaries to produce oestrogen
Oestrogen- Is produced by the
ovaries, Causes pituitary to produce
LH, Inhibits further release of FSH
LH- Produced by the pituitary gland,
Stimulate the release of an egg
during the cycle
Hormones are chemical messengers
Fertility
Oestrogen prevents the release of an egg, controlling fertility
FSH and LH help women to get pregnant
IVF- In-vitro fertilisation
Plants
Auxins
Auxins are produced in the tip of the stem
Sunlight breaks down the side of auxins
Causing the roots or stems to bed
towards sun or water
Tropisms
Phototropism- Light
Geotropism- gravity
Hydrotropism- water
Thigmotropism- touch
Homeostasis
Constant internal environment
Iron content is regulated by kidneys
Temperature is controlled by the brain- 37 degrees
Sugar and water are also controlled by the body
Adaptations, Environmental change and Evolution
Adaptations
Large surface area
compared to volume-
losing more body loss
Good efficiency
with water
Camoflage
Teeth, claws,
poisons, warning
colours
Organisms compete for resources to survive- light
water space shelter mates nutrients food
Environmental change biotic (living)
and abiotic (non-living) factors
Living- diseases,
predators, prey,
competitors
Measured using living indicators-
Lichen, sewage-bacteria