Question

Study the following and choose the correct statements:
I. Haemophilia-A and Haemophilia-B are X-linked disorders due to recessive genes
II. Sickle cell anaemia is caused by a point mutation where valine at 6th position is replaced by glutamic acid
III. Protonopia is red colour blindness
IV. Phenyl ketonuria is an allosomal metabolic genetic disorder

• A. I, III
• B. II, IV
• C. I, II
• D. III, IV

Hint:

X-linked disorders manifest predominantly in males. Always verify amino acid changes carefully for point mutations. Use mnemonics to remember red/green blindness types.

Answer 1

The Correct Option is A

I. True — Haemophilia-A/B are X-linked recessive disorders. II. False — In sickle cell anaemia, glutamic acid is replaced by valine, not vice versa. III. True — Protonopia is red colour blindness (red cones defect). IV. False — Phenylketonuria is autosomal recessive, not allosomal.