Question

Choose the incorrect statement(s) from the following.
(A) Gene for eye color in Drosophila is located on X-chromosome
(B) Red eye colour is dominant over white eye color
(C) White eye color is considered as wild type
(D) Recessive homozygous condition for eye color is lethal

• A. A and B
• B. B and C
• C. C and D
• D. A and D

Answer 1

The correct option is C C and D

Eye colour variation in Drosophila is one of the heritable variations which can be seen with a low-power microscope where red eye is dominant over white. The red eye characteristic is known as the wild type because it is the most common in the natural population. As the reciprocal cross ratios differ from each other it suggests that the gene for eye colour is located on the X chromosome. The recessive homozygous condition for eye color is not lethal, as a cross between a white-eyed male $\left(X^{w}Y\right)$ and a red-eyed female $\left(X^{+}{X}^w\right)$ results in a 1:1:1:1 ratio of red-eyed females to white-eyed females to red-eyed males to white-eyed males.