Question

If a mutation occurs in a gamete, which of the following is most likely to result?

If the mutation occurs on a recessive gene, it will most likely be expressed.

If the mutation is non-disjunctive then an extra chromosome could be in every cell of the offspring.

The mutation will not always cause the offspring to be genetically disadvantaged.

The mutation will not be passed on to the offspring.

Answer 1

You should start using process of elimination to solve these problems. Do you have a hunch about which options it isn't, and why so?

Answer 2

* why not.

Answer 3

D is not right, right?

Answer 4

That is right. Gametes are exactly what are passed on to future generations, so it's silly to say that a mutation in a gamete won't be passed on.

I think it's also not A. Recessive alleles aren't expressed anyway, so if a mutation occurs in one it probably won't have any effect on the overall phenotype of the organism.

Answer 5

is it C?

Answer 6

Here the question is ambiguous: a case could be made for either.

C is absolutely a possibility - mutations are not always bad. Sometimes they confer a gain of function on the protein it codes for, or it affects the organism in some other good way.

But it could also be B. A nondisjunction is when chromosomes don't sort properly during cell division: one daughter cell winds up with an extra and the other daughter cell winds up with one less than it should have. This imbalance is perpetuated in all those cells' offspring if they divide.

The question asks which is more likely - and I think it's B. The one about non-disjunction.