I. Haemophilia is a sex-linked recessive disease.
II. Down's syndrome is due to aneuploidy.
III. Phenylketonuria is an autosomal recessive gene disorder.
IV. Sickle-cell anaemia is an X-linked recessive gene disorder.
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(a) II and IV are correct
(b) I, III and IV are correct
(c) I, II and III are correct
(d) I and IV are correct
[NEET 2016, Phase 1]
Correct Option (c)
Reason : Sickle-cell anaemia is an autosomal recessive gene disorder in which sickle-celled RBCs are formed instead of normal ones.
They carry very less content of O₂ as their haemoglobin is malformed.
The person suffering from this disease show symptoms of anaemia.