1999 General Studies, all questions
UPSC Prelims 1999 · General Studies
Question 114: Science and Technology
Which one of the following genetic diseases is sex-linked?
aRoyal haemophilia
bTay Sachs disease
cCystic fibrosis
dHypertension
AnswerThe answer is (a).
Haemophilia is a sex-linked recessive disease: the gene lies on the X chromosome, so it is passed mostly from carrier mothers to sons. 'Royal haemophilia' ran through the descendants of Queen Victoria in European royal families. Tay-Sachs disease and cystic fibrosis are autosomal recessive disorders, and hypertension is a multifactorial condition. Remember: haemophilia and colour blindness are X-linked.
Why each option is right or wrong
- (a) Right. Haemophilia is X-linked.
- (b) Wrong. Tay-Sachs disease is autosomal recessive.
- (c) Wrong. Cystic fibrosis is autosomal recessive.
- (d) Wrong. Hypertension is multifactorial and not sex-linked.
Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 1999, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.