Question

Consider a gene with four alleles a1, a2, a3, and a4. in the cross a1a2 × a3a3, how many offspring genotypes are possible?

Answer 1

With allele crossing we can represent it for an easier understanding by a table like the following:
_______Parent 1_______
| |____a1___|____a2____
|a3| a1a3 | a2a3
Parent 2|__|_________|__________
|a3| a1a3 | a2a3
| | |

It is possible to form two genotypes. When the there is one homozygous individual, the variety in the combination will depend solely on the variation of the other parent.