Question

Anish is having colour-blindness and married to Sheela, who is not colour-blind. What is the chance that their son will have the disease?

• A. $100\%$
• B. $50\%$
• C. $25\%$
• D. $0\%$

Answer 1

Answer: (D)

$0\%$

Color-blindness is a recessive sex linked trait. The genotype of the woman will be X${}^C$X${}^C$ because she has normal vision. The woman married the man who is colorblind. The genotype of the man will be X${}^c$Y.

The offsprings will be

X${}^C$X${}^c$ two normal girls because there is no recessive allele and

X${}^C$Y two normal boys because there are no recessive alleles for the disease.

There are no children with colour blindness. So, the probabaility is 0%.

Thus, the correct answer is option D.