Class 12 NEET Biology Principles of Inheritance and Variation Questions Part 2

Haemophilia is an X-linked recessive disease. It occurs due to mutation in gene present on the X chromosome. It is most commonly seen in human males as males have only one copy of X chromosome and only one altered copy of the gene is sufficient to cause the disease. In females, there are two copies of X chromosomes and two altered copies of gene is required to cause the disease. Since it is recessive disease, one copy of altered gene in females will result in carrier state.
Thus, the correct answer is option C.