Question

In Drossophila normal wings are due to the genotype
a. Vgno
Vgui
b. Vgst
d. Vgno
a.Vgni
c.Vg+​

Answer 1

Explanation:

The ratio of various phenotypes can be calculated as follows:

Normal winged, normal eyed : 299

Normal winged, eyeless : 106

Vestigial winged, normal eyed : 99

Vestigial winged, eyeless : 33

The ratio is 299: 106: 99: 33 = 9.06: 3.2: 3: 1 = 9:3:3:1

This ratio shows that parents are heterozygous for the dominant traits as this ratio matches the Mendelian dihybrid ratio. Hence the genotypes of parents will be +vg/+ey i.e. normal winged, normal eyed. So, the correct is '+vg/+ey x +vg/+ey'.