Question

What proportion of the offspring obtained from cross AABBCC × AaBbCc will be completely heterozygous for all genes segregated independently?

• A. 1/16
• B. 1/8
• C. 1/4
• D. 1/2

Answer 1

The correct option is B 1/8

Since one parent is homozygous AABBCC the genotype formed will be only 1 type i.e. ABC.
The other parent is heterozygous for all genes.
Number of genotypes= $2^n$, where n is the number of heterozygotes
AaBbCc = $2^3$ = 8
About 1/8th or 12.5% of total offspring will be heterozygous at all three-locus.