Question

If a wild type eyed female drosophila is crossed to a white eyed male, what will be the percentage of their progeny with white eyes.

(a) 1

(b) None

(c) Half

(d) 1/4

I had been asked this question during an interview.

My question is taken from Multiple Alleles topic in chapter Extension and Deviation from Mendelian Genetic Principles of Cytogenetics

Answer 1

The correct answer is (b) None

The best explanation: Eye colour is present on the X chromosome , so the females of F1 will be heterozygous red eyed(wild-type), and the males will have only one eye colour allele from mother which would be for red eyes.