In fruit flies, red eyes (p+) is dominant to purple eyes (p) and normal wings (v
ID: 280017 • Letter: I
Question
In fruit flies, red eyes (p+) is dominant to purple eyes (p) and normal wings (v+) is dominant to vestigial wings (v). These genes are linked with 20 map units between them.
A pure-breeding red-eyed fly with normal wings was crossed with a pure-breeding purple-eyed fly with vestigial wings. All of the F1 had a wild type phenotype.
1. Which of the following represents the arrangement of alleles on the F1 chromosome?
a. p+v/pv+
b. p+v+/pv
c. pv/pv
d. pp/v+v+
2. If the F1 is mated in a testcross, what percentage of the progeny would you expect to have the wild type phenotype?
a. 20% b. 10% c. 80% d. 90% e. 40%
Explanation / Answer
1. F1 generation should have essentially p+v+ genes for wildtype phenotype. Hence option B is correct.
2. If F1 generation test crossed then there will be having 50% having wild type phenotype.