Question

A normal woman whose father was colour blind marries a normal man. The progeny would be.

• A. Sons normal, daughters colour blind
• B. Sons colour blind, daughters normal
• C. $50\%$ sons colour blind, remaining $50\%$ sons and all daughters phenotypically normal
• D. Both sons and daughters are colour blind

Answer 1

Answer: (C)

$50\%$ sons colour blind, remaining $50\%$ sons and all daughters phenotypically normal

The genotype of the normal woman with colour blind father = XXc

The genotype of normal man = XY

Morgan and his group found that when genes were grouped on the same chromosome, some genes were very tightly linked (showed very low recombination), while others were loosely linked (showed higher recombination). Recombination is a process of rearrangement of genes during meiosis so that a gamete contains a haploid genotype with a new gene combination.

So, the correct answer is '50% sons colour blind, remaining 50% sons and all daughters phenotypically normal'.