What are the 5 food groups?
Carbohydrates, fats, proteins, fibre & vitamins/minerals
what do fats and carbohydrates do?
release energy (+keep you warm)
What are proteins needed for?
Cell growth, repair and replacement
what is Fibre needed for?
to keep everything moving smoothly through the digestive system
What are vitamins/minerals needed for?
to keep skin, bones and blood healthy
What is the metabolic rate?
the speed at which chemical reactions take place inside the cytoplasm to release energy from the food.
What factors vary the speed of metabolic rate?
- gender
- age
- muscle to fat proportion
- genetics
What are the factors affecting health?
unbalanced diet, exercise and inheritance
What can obesity cause?
arthritis, diabetes, high blood pressure, heart disease and some kinds of cancer
What can too much fat cause?
increases blood cholesterol
What can too much salt cause?
high blood pressure and heart problems
What can malnourishment cause?
slow growth, fatigue, poor infection resistance
What is Bacteria?
small cells that reproduce rapidly inside your body while damaging cells and producing toxins
What is a virus?
not cells but things that invade your cells and replicate themselves. The cell will then burst releasing new viruses and making you feel ill.
What things help prevent pathogens entering your body?
skin, mucus and hair
How do white blood cells get rid of microbes?
1) engulf the pathogen and digest it.
2) produce antibodies
3) produce antitoxins which counteract toxins produced by bacteria
How do antibodies work?
- the bacteria has a unique surface (antigen)
- when white blood cells come across foreign antigens the produce proteins called antibodies to lock into and destroy the invading cell
How is a person immune?
if their white blood cells have produced antibodies for the same antigen before the white blood cell will ‘remember’ them and will be produced more rapidly when needed.
what is vaccination?
the injection of dead or inactive micro-organisms
What is the difference between painkillers and antibiotics?
painkillers relieve the symptoms whereas antibiotics kill the bacteria
What is an example of a bacteria that has grown resistant to antibiotics?
MRSA
What did semmelweise find out?
he believed that doctors were spreading diseases on their unwashed hands so he made them wash them in a antiseptic solution which cut the death rate.
what are the 5 sense organs?
1) Eyes
2) Ears
3) Nose
4) Tongue
5) Skin
What are the 5 receptors?
1) Light receptors
2) Sound and balance receptors
3) Smell receptors
4) Taste receptors
5) Sensitive to touch, pressure, pain and temperature
What is a relay neurone?
The nerve cells that carry signals from the sensory neurone to the motor neurone
What is a sensory neurone?
The nerve cells that carry signals from the receptors in the sense organs to the central nervous system.
What is a motor neurone?
the nerve cells that carry signals from the central nervous system to the effector muscles or glands
What is an effector?
respond differently (e.g. muscles contract and glands secret hormones)
What is a stimulus?
a change in environment
What is the synapse?
the connection between 2 neurones, the nerve signal is transferred by chemicals which diffuse across the gap.
What does the body need to control?
ion content, water content, blood sugar and temperature
How is water lost?
by sweating, breathing and urinating
What is FSH?
a hormone produced in the pituitary gland.
causes eggs to mature and stimulates the production of oestrogen
What is LH?
a hormone produced in the pituitary gland.
causes eggs to be released
What is oestrogen?
a hormone produced in the ovaries
stimulates the production of LH and prohibits the production of FSH
How does IVF work?
LH and FSH are given then eggs are collected. They are fertilised in a lab and when it becomes a tiny ball of cells it is transferred into the womens uterus.
What is a hormone?
a chemical messenger sent in the blood
What are the two tropisms caused by auxin
phototropism and geotropism
How can plant hormones be used in agriculture?
They can be used to kill and grow plants (fertiliser)
in the roots auxin acculumates
near moisture, with gravity inhibiting growth
in the shoots auxin acculmulates
in the shade,with gravity causing elongation
What is a drug?
a substance that changes the chemical makeup of the body
what are the three types of drug?
medicinal, Recreational and performance enhancing
What are the 3 stages of drug testing?
1) tested on human cells and tissues in the lab
2) testing drugs on live animals( to see if its toxic, if it workds and correct dosages)
3) Testing on healthy human volunteers in a clinical trial
What is a double blind trial?
is when the drug and the placebo are given but neither the doctors or patients know if they have the drug or not.
What is thalidomide?
A drug intended as a sleeping pill and was found to be effective for treating morning sickness in pregnant women.
Unfortunately it had not been tested for this and cause abnormal limb development.
it is now being used to treat leprosy
How are cannabis and hard drug use connected?
- stepping stone drug (desire to try new drugs)
- gateway drug (bring the users in to contact with hard drug dealers)
- certain people are more likely to take drugs generally.
The effect of legal drugs such as smoking and alcohol may be biggere because more people use them. what are these effects?
- disease (lung cancer and liver disease)
- causes accidents e.g. car accidents
- causes sorrow and depression
What are anabolic steroids?
drugs used to increase muscle size
What are stimulants?
Drugs that increase the heart rate.
What are statins?
prescribed drugs that lower the risk of heart disease
What are the positives of performance enhancing drugs?
sport isn’t fair anyway (e.g. equipment, coaches) and athletes should be able to decide on their own
What are the negatives of performance enhancing drugs?
unfair if people gain an advantage and the athletes may not be informed of the health issues.
What is variation?
when organisms of the same species have differences e.g. heights
The variation can be caused by genes or by the environment
what is inside a cell?
nucleus -> chromosomes (23 pairs) -> gene -> DNA
What is sexual reproduction?
has 2 parents and a mixture of genes.
is the fusions of the female and male gametes
What is asexual reproduction?
has 1 parent and no fusion of gametes, creates genetically identical clones
How can you clone plants?
cuttings and tissue culture
What is an embryo transplant?
where gametes are chosen from prize stock and fertilised the embryos are then implanted into cows for ideal offspring.
What is adult cell cloning?
where an egg cell has its genetic material removed and replaced with the nucleus of a body cell. it is given an electric shock to start the division process.
What are the issues of cloning?
reduced gene pool
not as healthy
What are enzymes used to do?
cut an paste genes
What are the pros of GM crops?
pros: increased yield & contains more nutrients
What is the theory of evolution?
billions of years ago life on earth began as simple organisms from which all the more complex organisms evolved.
What is an evolutionary relationship?
how living things are related
What is an ecological relationship?
how living things living with each other (e.g. sharks and dolphins)
What is Darwins theory of natural selection?
1) individuals within a species show variation because of differences in their genes
2) individuals with characteristics that make them better suited to the environment have a better chance of survival so are more likely to breed successfully
3) therefore the good genes are passed on to the next generation
Evolution can occur due to …
mutations
Why was Darwin’s Theory not believed?
because it went against religion, there wasn’t enough evidence and they didn’t know about genes.
What did Lamarks theory say?
that characteristics were developed during an organisms life time and passed down to the next generation
What was Thalidomide originally intended for?
sleeping pills
What was Thalidomide found to be useful for?
morning sickness in pregnant women (and later leprosy)
What did Thalidomide cause in babies?
abnormal limp development
What happens when a person becomes dependent on a drug?
changes to chemical processes
What is an independent company?
Another company that is not involved in the process of making something
Why are data loggers good?
- continuous readings
• do not need to be there
• (more likely to be) accurate
• reduces human error
How is something genetically modified?
• wanted gene cut out using enzymes • (gene) transferred to chromosome • at an early stage of development
what are statins?
- used to lower the risk of heart and circulatory disease
How can you reduce the amount of antibiotic resistant bacteria?
reduce the number of anti-biotics used especially for non-serious viral/infectious disease
What are the living factors what cause population changes
- infectious disease
- number of predators
- availability of food
- number or types of competitors
What is a gene?
a short length of the chromosome which controls the characteristics for development
What is a balanced diet?
The right amount of each amount of food provides the correct amount of energy for individual peoples needs
What is a Chromosome?
carry genes. 23 pairs
difference between nerves and hormones?
nerves are fast hormones are slow
nerves act for a short time hormones act for a long time
nerves act on a precise area hormones act on a general area
What are the cons of GM crops?
cons: affect wild plants, may not be safe, genes may find there way into weeds which may grow to be resistant.
pros of IVF?
helps women get pregnant
cons of IVF
- doesnt always work
- multiple pregnacies
- expenisve
pros of contraceptive pill?
effective at preventing pregnancy
reduces risk of getting some types of cancer
cons of contraceptive pill?
side effects such a nausea and fluid retention
doesn’t protect against stds
how are desert animals adapted?
large surface area compared to volume
efficient with water (don’t sweat/ concentrated urine)
thin layers of body fat
camoflague
How are desert plants adapted?
small surface area compared to volume
water storage tissues
maximising water absorbtion
How are arctic animals adapted?
small surface area compared to volume
well insulated
comoflague
what do plants need to survive?
light, space, water and mineral
What do animals need from the soil?
space, food, water and mates
What does lichen indicate?
level of pollution (lots of lichen shows clean air with little sulfur)
What does mayfly larvae indicate?
clean water
What do sludgeworms or maggots indicate?
very high level of water pollution
How can you clone plants with cuttings?
gardeners take cuttings from a good parent plant which produced genetically identical copies. it is quick and cheap.
How can you clone plants using tissue culture?
are few plant cells are put into a growth medium with hormones and they grow into new plants. they can be made quickly in very little space and can be done all year