how many genotypes will be produced by crossing 2 alleles "a" and "A" ? N tell me. How ?
- HollyLv 78 years agoFavorite Answer
I think you're asking if you crossed parents with Aa and Aa genotypes, what would come out of it?
Ok, let's assume that this is for hair color, and brown is dominant, blonde is recessive.
AA = brown
Aa = brown
aa = blonde
Use a punnet square:
A. AA Aa
a .Aa aa
So, if you cross Aa and Aa, you will get the following genotypes:
So that means that 25% of the offspring with have the homozygous dominant phenotype, 50% will have the heterozygous dominant phenotype, and 25% would have the homozygous recessive phenotype.
So 75% of the offspring would have brown hair
25% would have blonde hair.
- SlickterpLv 78 years ago
Doesn't make sense. Genes each have 2 alleles. So do you mean crossing an aA with an aA?
By having just two alleles, you would have one genotype - aA.
Crossing aA and aA you wouldget 3 genotypes - aa, AA, and aA
- 8 years ago
genes have 2 alleles
- Anonymous8 years ago
for aa & AA = only Aa
for aa & Aa = Aa & aa
you should have to say more detailsSource(s): sounds like you are still in grade 4 /5