Question

If a polygenic trait is controlled by three gene pairs then what will be the probability of individuals in $F_2$ generation showing exacts phenotype to F${}_1$ progeny?

• A. 6/16
• B. 4/64
• C. 20/64
• D. 1/16

Answer 1

Answer: (C)

20/64

For a polygenic trait controlled by two gene pairs, the probability of individuals in F${}_2$ generation showing exact phenotype to F${}_1$ is 20. E.g., a creative between pure white and negro human skin color yields mullet in F ${}_1$ and in F ${}_2$ where phenotype ratio I :6:15:20:15:6:1 where mullet is 20.

So, the correct answer is option C.