Question

In a genetic cross having recessive epistasis, F₂ phenotypic ratio would be

• A. 9:6:1
• B. 15 : 1.
• C. 9 : 3 : 4
• D. 12 : 3 : 1

Answer 1

The correct option is C

9 : 3 : 4

In a genetic cross having recessive epistasis, F₂ phenotypic ratio would be 9:3 :4. The recessive epistasis is illustrated by coat colour in mouse, the coat colour is determined by A/a pair, recessive allele b is epistatic over A/a. Thus, in the presence of bb, both A and aa give the same phenotype (albino).
The F₂ ratio is generally 9 : 3 : 4.