AP BIOLOGY

Detailed explanation-1: -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-2: -Mutational effects can be beneficial, harmful, or neutral, depending on their context or location. Most non-neutral mutations are deleterious. In general, the more base pairs that are affected by a mutation, the larger the effect of the mutation, and the larger the mutation’s probability of being deleterious.

Detailed explanation-3: -Answer and Explanation: “All mutations are harmful and increase the risk of disease such as cancer” is a false statement. It should read “Some mutation may be harmful and increase the risk of diseases such as cancer, but many are beneficial. The majority of mutations are nearly neutral or harmful.

Detailed explanation-4: -By the same token, any random change in a gene’s DNA is likely to result in a protein that does not function normally or may not function at all. Such mutations are likely to be harmful. Harmful mutations may cause genetic disorders or cancer. A genetic disorder is a disease caused by a mutation in one or a few genes.

Detailed explanation-5: -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.