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There are 3 hormones mentioned in the AQA GCSE Biology specification. These are FSH (follicle stimulating hormone), LH (leuteinising hormone), and oestrogen. FSH and LH are produced by the pituitary gland...

Raised plasma glucose concentration means greater entrance of glucose into beta cells in the Islet of Langerhans in the pancreas. This increased concentration glucose means greater metabolism of glucose, ...

A reflex action occurs very quickly, and does not involve the brain. The stimulus (e.g. a flame) is sensed by the receptor (the skin). The sensory neurone attached to the receptor sends an impulse to the ...

DNA transcription is the process of copying the DNA strand in order to make mRNA that is needed for protein synthesis. Firstly, RNA polymerase attaches to the double helix of DNA, this unwound by the RNA ...

When two populations are geographically isolated they can no longer interbreed. There is no mixing of genes between the groups and over generations differences build up between the populations. This is ca...