AP BIOLOGY

Detailed explanation-1: -Most mutations are corrected by DNA repair processes in the cell. In rare cases, however, mutations can accumulate and cause genetic diseases such as cancer. Depending on students’ background, it may be helpful to pause the animation at various points to discuss different structures or molecules.

Detailed explanation-2: -No; only a small percentage of variants cause genetic disorders-most have no impact on health or development. For example, some variants alter a gene’s DNA sequence but do not change the function of the protein made from the gene.

Detailed explanation-3: -B. Silent mutations are a result of the redundancy (degeneracy) of the genetic code: This is false, as silent mutations are the result of a base substitution that has no discernible effect on the amino acid sequence of a protein.

Detailed explanation-4: -The majority of mutations have neither negative nor positive effects on the organism in which they occur. These mutations are called neutral mutations. Examples include silent point mutations. They are neutral because they do not change the a mino acid s in the proteins they encode.