AP BIOLOGY

Detailed explanation-1: -A point mutation occurs in a genome when a single base pair is added, deleted or changed. While most point mutations are benign, they can also have various functional consequences, including changes in gene expression or alterations in encoded proteins.

Detailed explanation-2: -Base Substitutions Single base substitutions are called point mutations, recall the point mutation Glu—–> Val which causes sickle-cell disease. Point mutations are the most common type of mutation and there are two types.

Detailed explanation-3: -Base substitution Base substitutions are the simplest type of gene-level mutation, and they involve the swapping of one nucleotide for another during DNA replication. For example, during replication, a thymine nucleotide might be inserted in place of a guanine nucleotide.

Detailed explanation-4: -A genetic alteration caused by the substitution of a single nucleotide for another nucleotide. Also called point variant.

Detailed explanation-5: -A substitution is a mutation that exchanges one base for another (i.e., a change in a single “chemical letter” such as switching an A to a G). Such a substitution could: change a codon to one that encodes a different amino acid and cause a small change in the protein produced.