Multiple choice

If the father is a haemophilic and the mother is a carrier, then what are the chances of their son being haemophilic?

  1. 0%

  2. 50%

  3. 75%

  4. 100%

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition.