AP BIOLOGY

Detailed explanation-1: -A mutation (Section 14.1) is a change in the nucleotide sequence of a short region of a genome (Figure 14.1A). Many mutations are point mutations that replace one nucleotide with another; others involve insertion or deletion of one or a few nucleotides.

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. Meanwhile, larger mutations can affect many genes on a chromosome.

Detailed explanation-3: -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-4: -Usually, a chromosomal mutation happens because of a change in chromosome structures, chromosomal rearrangement, or other chromosomal abnormalities such as a change in chromosome number or missing chromosome. As previously stated, these often take place because there are issues during crossing over or cell division.

Detailed explanation-5: -An insertion changes the DNA sequence by adding one or more nucleotides to the gene. As a result, the protein made from the gene may not function properly. A deletion changes the DNA sequence by removing at least one nucleotide in a gene.