Cambridge O Level Biology · Syllabus 5090 · Inheritance
Sources of Genetic Variation
What is Sources of Genetic Variation?
The processes that produce genetic differences between individuals of the same species: mutation, meiosis, random mating and random fertilisation. Mutation is the only one that creates a new allele, by changing the base sequence of DNA. Meiosis puts a different combination of the existing alleles into each gamete. Random mating determines which two individuals breed together, and random fertilisation determines which particular gametes fuse, so that each offspring receives a combination of alleles that is unlikely to have occurred before. Together these processes supply the inherited variation on which natural selection and artificial selection act.
This definition is part of the Inheritance chapter in Cambridge O Level Biology.