Why are gametes much more prone to mutation than somatic cells?

a) They only have one set chromosome, and thus, they are unstable.
b) They only have one set of chromosomes, so they are more likely to express recessive deleterious alleles.
c) They only have one set of chromosomes, and thus, no template for repair.
d) Gametes are not more prone to mutation than somatic cells.
e) None of the above


The correct answer is…

C. First of all, it is important for you to realize that mutations are possible in gamete, even though there is no actual replication happening. This is because there are several things that can cause mutations aside from replication (and the errors of DNA polymerase) – including UV light, and other chemical mutagens (ethidium bromide). With that said, when these sorts of mutations happen in normal somatic cells, they actually have no problem repairing it because they two sets of each chromosome. In this case, the mutated chromosome can then use its partner as a template (through complex mechanisms) and rectify its mistake. However, in a gamete, there is only one set of chromosomes, so this sort of correction mechanism is not possible.