Phagocytosis - this is when the white blood cell engulfs the foreign cells

Antigens come in different shapes ,meaning that the antibodies would have to be produced at a precise shape the same as the antigen.

Memory cells remember what the pathogen was and produce faster as there was the same antigen before, this makes the person feel less ill.

Antitoxin - They neutralize the toxins produced by the pathogen to make you feel less ill.

Dose - how much of the drug should be given without causing harm?

Double blind trial - where the patient and doctor doesn't know that they are given the placebo or the real drug, this is to test the placebo effect.

A change in surrounding, internal or external, which leads to a response.

Receptors are the cells that detect stimuli. Sensory neurons carry information from receptor to CNS.

Coordinator is CNS. It decides what to do. Then sends information to the muscle or glands

Receive the information from CNS through the motor neurons.

Muscle or gland does what ever it needs. e.g if arm feels something hot on it, it moves away from the heat.

If the level of something is too low, the receptor would detect it, CNS would organise a response and the effector would produce a response to increase the level.

If the level of something in the body is too high, the receptor would detect it, the CNS would organise a response and then it would be sent to the effector which counteracts the change and decreases the level

The endocrine system is a collection of glands which secrete hormones

Pancreas - Produces insulin which is used to regulate blood glucose level.

Ovaries (females) - Produce oestrogen which is used in menstrual cycle.

Thyroid gland - Produces thyroxine which regulates things like rate of metabolism, heart rate and temperature.

Testes (male) - Produce testosterone which controls puberty and sperm production

Pituitary gland - aka, 'Master Gland'. Produces many hormones to regulate body conditions. These hormones act on other glands directing them to release hormones that brind change.

Adrenal gland - Produces adrenaline which is used for 'fight or flight' responses.

Adrenaline - prepares you for 'fight or flight'. Released by the adrenal gland which is just above the kidneys. This triggers a mechanism which increases the supply of oxygen and glucose to cells in muscles and the brain.

Thyroxine is released in response to thyroid stimulating hormone (TSH) which is released from the pituitary gland. When level of thyroxine in blood is too high, the secretion (release) of TSH is stopped. This reduces amount of thyroxine so the level of blood falls back to normal.

Genetic causes - Differences in gene which the individual has inherited, from their parents, this is genetic variation

Environmental causes - Difference in environmental conditions which the individual has developed.

Mutations can make the individual better suited for its environment, which leads to natural selection.

He concluded that organisms which had the most suitable characteristics for the environment would be more successful competitors and would more likely to survive. These are said to be well adapted.

Successful organisms would reproduce and pass the characteristics on.

Less well adapted would less likely to reproduce so not likely to pass on their gene

Benificial characteristics become common in population and species would change.

Antibiotic resistance - When they mutate, they become resistant to antibiotics. So when bacteria reproduces, it passes on the resistance which means that eventually the whole population of a bacteria would be resistant. This means that the living organism would pass the antibiotic resistance genes on.

Gradual replacement by minerals (most happen this way) - Things which don't decays easily, teeth, shells, bones etc. can last a long time when buried. When these decay they form a rock like substance shaped like the original hard part. Eventually someone digs it up.

Preservation - In amber and tar pits, there's no oxygen or moisture so decay microbes wont survive, which means it won't decay. In glaciers its too cold for decay microbes and peat bogs are too acidic for decay microbes.

Cast and impressions - Sometimes fossils are burried in a soft material like clay. Clay then hardens and when the fossil decays, the clay keeps the shape of the fossil. Things like footprints can leave a impression when pressed into these materials.

A catastrophic event happens to kill them all (e.g. volcanic explosion.

Contains true bacteria. Although they look similar to the Archaea, there are lots of biochemical differences between them.

A different type of prokaryotic cell to bacteria, and were first found in extreme places such as hot springs and salt lakes.

A broad range of organisms including fungi, plants, animals and protists.

3) Using a different enzyme, stick the desired gene into the plasmid vector.

2) Using the same enzyme, cut the plasmid vector which creates a space for the desired gene.

1) The gene for the desired characteristic is isolated and cut out using enzymes.

6) Transfer into animals and plants at a early stage (embryo) so it developed with its desired gene.

Resistant to weed killers mean the farmer can spray the whole field without damaging the crops but just the weeds.

Being resistant to insects means it will not hinder/damage the growth of plants.

Uncertain of long term health on humans if consuming GM crops.

Population of wild flowers and insects may decrease if crops are successful.

So it ensure that all the cell of the organisms will contain the desired gene even when they divide.

Parents with the desired gene are chosen and bred together. Offspring breeds and then after many generations, the offspring show the desired gene.

When breeding people choose the "best" animals or plants which reduces the gene pool, this can cause health problems because there's more chance of the organism inheriting harmful genetic defects. e.g. pugs often have breathing problems.

If blood glucose becomes too low, the pancreas secretes a hormone called Glycogon, this regulates blood glucose by releasing the glucose stored in the liver.