AP BIOLOGY

Detailed explanation-1: -But some replication errors make it past these mechanisms, thus becoming permanent mutations. These altered nucleotide sequences can then be passed down from one cellular generation to the next, and if they occur in cells that give rise to gametes, they can even be transmitted to subsequent organismal generations.

Detailed explanation-2: -Most mistakes are corrected, but if they are not, they may result in a mutation defined as a permanent change in the DNA sequence. Mutations can be of many types, such as substitution, deletion, insertion, and translocation. Mutations in repair genes may lead to serious consequences such as cancer.

Detailed explanation-3: -Mutations happen for several reasons. Most of the mutations that we think matter to evolution are “naturally-occurring.” For example, when a cell divides, it makes a copy of its DNA-and sometimes the copy is not quite perfect. That small difference from the original DNA sequence is a mutation.

Detailed explanation-4: -Nucleotide excision repair is another pathway used to remove and replace damaged bases. Nucleotide excision repair detects and corrects types of damage that distort the DNA double helix.