Question

Precentage of offsprings with genotype aabbcc from a cross aabbcc and aabbcc would be

Answer 1

I think you want to know the proportion of individuals who are heterozygous for all the three genes.

The proportion of individuals with a particular genotype depends on the proportion of gametes that the individuals have received from their parents.

We need to find the proportion of individuals with the genotype AaBbCc. The parent with genotype aaBBcc can produce only a single type of gamete; one having the genotype aBc. Clearly the other three alleles in the individual were inherited from the other parent. The genotype of the gamete from the other parent is, thus, AbC.

Now, this parent is heterozygous for all three genes. It will produce (2^3)=8 type of gametes in equal proportion. The gamete with the genotype AbC is one of these. So it's proportion will be simply 1/8.

Hence, the proportion of the individuals with genotype AaBbCc is 1×(1/8)=1/8

Answer 2

We need to find the proportion of individuals with the genotype AaBbCc. The parent with genotype aaBBcc can produce only a single type of gamete; one having the genotype aBc. Clearly the other three alleles in the individual were inherited from the other parent. The genotype of the gamete from the other parent is, thus, AbC.

Now, this parent is heterozygous for all three genes. It will produce (2^3)=8 type of gametes in equal proportion. The gamete with the genotype AbC is one of these. So it's proportion will be simply 1/8.

Hence, the proportion of the individuals with genotype AaBbCc is 1×(1/8)=1/8