Question

If you cross a white eyed female drosophila with a red eyed male drosophila, what will be the colour of eyes for their male and female offspring?

(a) Both red eyed

(b) Both white eyed

(c) Red eyed daughter and white eyed son

(d) Red eyed son and white eyed daughter

This question was posed to me at a job interview.

I need to ask this question from Chromosomal Theory of Inheritance topic in chapter Chromosomal Basis of Inheritance of Cytogenetics

Answer 1

Correct answer is (c) Red eyed daughter and white eyed son

Explanation: The eye colour of Drosophila is an X linked gene. So as the female is homozygous recessive white and the male has on red allele and one Y chromosome, sons will only get Y chromosomes from father. Sons will thus be white eyed while daughters will be red eyed.