25 POINTs and BRAINLIST i need help ASAP
Question 17 (2 points)
A geneticist found that a particular mutation had no effect on the protein produced by the gene. What type of mutation would this be called?

Question 17 options:

silent mutation

frameshift mutation

point mutation

missense mutation

Question 18 (2 points)
If a mutation in a gene does not result in a change in protein function, the resulting effect is most likely to be:

Question 18 options:

neutral

not a mutation

harmful

beneficial

Question 19 (2 points)
If a mutation in a gene allows a protein to function more efficiently, the resulting effect is most likely to be:

Question 19 options:

neutral

harmful

beneficial

not a mutation

Question 17: Silent mutation.

Question 18: Neutral.

Question 19: Beneficial (but see explanation below).

Explanation:

17)

A silent mutation is defined as a change in coding DNA which does not have an effect in the amino acid produced during translation. Silent mutations are possible because the genetic code is degenerate, meaning that a given amino acid may be coded by more than one codon. For instance: a mutation changing AUGCUA to AUGCUG is likely to be silent, since both the CUA and CUG codons code for the same amino acid (Leucine).

Note that a silent mutation may well also be a point mutation (meaning: involving the change of a single nucleotide). In fact, the example given above would meet that criterion. However, the question as stated does not contain enough information for making that call in this particular case.

18)

This particular question asks us to extrapolate from a given level of organization (function of a specific type of protein) to a higher one (overall functioning and/or wellbeing of the whole organism). In general, it can be assumed that mutations which change a given protein’s sequence without altering its function will have a negligible effect on the organism’s fitness. Such mutations are therefore called neutral. Note that the neutrality of a mutation may not always be self-evident, however, due the fact that a given protein may have several functions, the measurement of which may not be feasible.

19)

The answer in this question really depends on which specific example one may happen to be working with. Broadly speaking, higher efficiency tends to be associated with beneficial effects (e.g. assume an increase in the efficiency of an enzyme which breaks down a certain type of toxic substance present in food). One may found counterexamples, however. Picture another enzyme, which normally plays a role in disaggregating blood clots during normal blood coagulation. An increase in its efficiency could potentially lead to premature disaggregation of clots and hence prolonged bleeding.