Variation revision

Variation is the differences which can occur between individuals of the same species

A group of interbreeding organisms whose offspring are fertile

• Variation is important to a species as it allows the population to adapt to a changing environment so it has a better chance of survival
• eg resistance and survival from a disease or colonising a new environment

As it is an important source of genetic variation

• Meiosis - gives rise to gametes which are not all the same
• Fertilisation - nuclei of two gametes fuse to form a zygote with different combination of genes
• Mutation - sometimes a change will occur in a gene and a new characteristic may be passed on

The characteristic number of chromosomes for every animal or plant

double

single