AP BIOLOGY

Detailed explanation-1: -Mutations can be beneficial, neutral, or harmful for the organism, but mutations do not “try” to supply what the organism “needs.” Factors in the environment may influence the rate of mutation but are not generally thought to influence the direction of mutation.

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: -It is well-known that most mutations arise spontaneously and they are, in general, either harmful or neutral. However, only a rare few are advantageous to the organism, as they increase its viability and reproductive ability (Darwinian fitness).

Detailed explanation-4: -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-5: -Many mutations are neutral and have no effect on the organism in which they occur. Some mutations are beneficial and improve fitness. An example is a mutation that confers antibiotic resistance in bacteria. Other mutations are harmful and decrease fitness, such as the mutations that cause genetic disorders or cancers .