Question

Raj with red-green color blindness (an X-linked recessive condition) has a color-blind father and a mother who is not color blind. Raj inherit his color blindness from which parent?

• A. No way to knowit could have been either one.
• B. His father
• C. His mother
• D. It had to come partly from both his mother and father.
• E. It had nothing to do with either his mother or father.

Answer 1

The correct option is C His mother

The red-green color blindness is an X-linked recessive condition. The father is colour blind and have the genotype as X${}^c$ Y. His mother is not colour blind and so she can have the genotype as XX or XX${}^c$. Raj is suffering from the disorder and will have same genotype as X${}^c$ Y, where X is inherited from the mother and Y from his father. So, the genotype of his mother is XX${}^c$ and he has received the colour blindness X gene from his mother.

Thus, the correct answer is option 'His mother'.