Question

Which of the following crosses would produce genotypic ratio of 1 : 2 : 1?

• A. AB $\times$ AB
• B. Ab $\times$ ab
• C. Ab $\times$ Ab
• D. ab $\times$ ab

Answer 1

The correct option is C Ab $\times$ Ab

A. AB x AB ® all progeny are of AB, genotypic ratio is 1:0

B. Ab x ab ® progeny shows genotypes Aa, Ab, ab, bb, genotypic ratio is 1:1:1:1

C. Ab x Ab ® progeny shows genotypes, AA, Ab, bb, genotypic ratio is 1:2:1

D. ab x ab ® all progeny shows same genotype ab, gentotypic ratio is 1:0.

So, the correct option is Ab x Ab.