Question

if a pea plant has the genotype AABbCC, what possible gametes can it form, and in what proportion can it form them?

Answer 1

Assuming independent assortment, just write out every combination you could have to find the possible gametes. In this case, ABC and AbC are the only possible gametes. They are also produced in a 1:1 ratio, meaning 50% of gametes are ABC and 50% are AbC.

Keep in mind that the A and C in both cases could come from EITHER A or C (you have two of each in your genotype). However, because the A and C loci are homozygous, you don't need to differentiate between the two A alleles or the two C alleles because they are equivalent in this case.