AP BIOLOGY

Detailed explanation-1: -Mutations are the original source of genetic variation. A mutation is a permanent alteration to a DNA sequence. De novo (new) mutations occur when there is an error during DNA replication that is not corrected by DNA repair enzymes.

Detailed explanation-2: -A mutation is a change in the sequence of an organism’s DNA.

Detailed explanation-3: -For a given population, there are three sources of variation: mutation, recombination and immigration of genes or deletion.

Detailed explanation-4: -The ultimate source of all genetic variation is mutation. Mutation is important as the first step of evolution because it creates a new DNA sequence for a particular gene, creating a new allele. Recombination also can create a new DNA sequence (a new allele) for a specific gene through intragenic recombination.

Detailed explanation-5: -What are the three sources of genetic variations? Mutation, gene flow, and sexual reproduction are the main sources of genetic variation.