Question

16. In which of the following situations are the phenotypes of F2 offspring expected to follow
the ratio of 9:3:3:1?
a. monohybrid cross for two unlinked traits
b. a monohybrid cross for two closely linked traits
c. a dihybrid cross for two unlinked traits
d. a dihybrid cross for two closely linked traits​

Answer 1

Answer:

C

Explanation:

The F2 offspring of a cross would follow the ratio of 9:3:3:1 only if the cross is a dihybrid for two unlinked traits.

There is nothing like a monohybrid cross for two traits. A cross involving two traits is a dihybrid cross. Hence, options a and b are out of the equation.

A dihybrid cross for two closely linked traits would produce F2 offspring in another ratio that is different from 9:3:3:1 depending on the linkage map.

Hence, the correct option is C.