Question

In a cross in Drosphila, the heterozygous animal with grey body $\left(b^{+}\right)$ and long wings $\left(v{g}^{+}\right)$ was crossed with an animal with black body and vestigial wings. The progeny has the animals in the following ratio : Grey vestigial 24; grey long 126; black long26 ; black vestigial 124. What is the frequency of recombinants in the population?

• A. 15.8
• B. 16.7
• C. 17.5
• D. 14.5

Answer 1

The correct option is B 16.7

Frequency of crossing over $=\frac{Numberofrecombinants}{Totalproperly}\times 100=\frac{50\times 100}{300}=16.7\%$ (i.e,) distance between the 2 genes is 16.7 map units.