NEET 2005
- Exam
- NEET
- Year
- 2005
- Subject
- Zoology
- Chapter
- Principles of Inheritance and Variation
NEET 2005 · Zoology · Principles of Inheritance and Variation
Haemophilia is more commonly seen in human males than in human...
Haemophilia is more commonly seen in human males than in human females because:
Options
- Aa greater proportion of girls die in infancy
- Bthis disease is due to a Y-linked recessive mutation
- Cthis disease is due to an X-linked recessive mutation
- Dthis disease is due to an X-linked dominant mutation.
Correct answer
C. this disease is due to an X-linked recessive mutation
Step-by-step solution
Haemophilia being a sex chromosome related recessive disorder has its gene present on chromosome. Since males have one and one chromosome, and the genes present on don't have counter genes on , only one affected gene (to be present on ) is required for the disease in males. While in females, there are chromosomes. For the disease to occur both the chromosomes should have the affected genes which is a rare chance. For this to be possible, the father of the female must be diseased while the mother must atleast be a carrier.