AP BIOLOGY

Detailed explanation-1: -Substitution, as related to genomics, is a type of mutation in which one nucleotide is replaced by a different nucleotide. The term can also refer to the replacement of one amino acid in a protein with a different amino acid.

Detailed explanation-2: -Some of the more common single-gene disorders include cystic fibrosis, hemochromatosis, Tay-Sachs, and sickle cell anemia. Even though these diseases are primarily caused by a single gene, several different mutations can result in the same disease but with varying degrees of severity and phenotype.

Detailed explanation-3: -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.