AP BIOLOGY

Detailed explanation-1: -A gene variant is a permanent change in the DNA sequence that makes up a gene. This type of genetic change used to be known as a gene mutation, but because changes in DNA do not always cause disease, it is thought that gene variant is a more accurate term.

Detailed explanation-2: -A mutation is a change in a genetic sequence. Mutations include changes as small as the substitution of a single DNA building block, or nucleotide base, with another nucleotide base.

Detailed explanation-3: -Gene variants (also known as mutations) can have varying effects on health, depending on where they occur and whether they alter the function of essential proteins. Variant types include the following: Substitution. This type of variant replaces one DNA building block (nucleotide) with another.