Question

Carrier female marries a normal visioned male. How many daughters would be colourblind carries?

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

Answer 1

The correct option is C $50\%$

Color-blindness is carried on the X chromosome. Men, being XY, will either be color-blind or not. Men cannot be carriers. Women, being XX, can be color-blind (if both X chromosomes carry the color-blindness gene), carriers (if only one of their X chromosomes carries the gene), or completely free of the gene.

If a carrier female marries a man that is not color blind it means they don’t carry the gene at all. If they have children:

• If they have a son, that son will have a 50% chance to be color blind.

• If they have a daughter, that daughter will have a 50% chance to be a carrier.

So, the correct answer is '50%'.