Question

In genetic complementation testing, crosses are performed between pure-breeding strains for recessive mutations that confer the same mutant phenotype. If the two mutations are in the same gene, then what phenotypic ratios would be expected among the progeny?

A. All of the F1 progeny would display the mutant phenotype associated with the parents.
B. There will be a 1:1 ratio of mutant to wild-type.
C. All of the F1 progeny would be wild-type.
D. All of the F1 progeny would display a novel mutant phenotype that differs from that of the parents.
The answer is not C.

Answer 1

Answer:

All of the F1 progeny would be wild-type.

If the two mutations are in different genes, then we expect complementation to occur (each mutant strain provides a functional copy of the gene that is defective in the other strain) and wild-type progeny to be produced