Question

Choose the correct answer from the alternatives given.

In fruit flies, the long wing is dominant to the vestigial wing. When heterozygous long-winged flies were crossed with vestigial-winged flies, 192 offsprings were produced. Of these, 101 had long wings and 91 had vestigial wings. If an exact Mendelian ratio had been obtained, then the number of each phenotype would have been Long-winged: vestigial-winged.

• A. Long winged 64, Vestigial winged - 128
• B. Long winged - 96, Vestigial winged 96.
• C. Long winged - 128, Vestigial winged 64
• D. Long winged - 192, Vestigial winged 0

Answer 1

Answer: (B)

Long winged - 96, Vestigial winged 96.

A cross between heterozygous long-winged flies and (homozygous) vestigial winged
flies represents an example of test cross, in which the exact Mendelian ratio of 1: 1 is obtained. i e. 96 long-winged flies and 96 vestigial winged flies.