Q.98. Match the following genetic disorders in Column I with associated typical chromosomal changes
mentioned in Column II
Column I
P. Klinefelter syndrome
Q. Down syndrome
R. Turner syndrome
S. Cri du chat syndrome
Column II
(i) 45, XO
(ii) 5 p minus
(iii) 47, XXY
(iv) Trisomy 21
(A) P-(iv), Q-(iii), R-(ii), S-(i)
(B) P-(iv), Q-(ii), R-(i), S-(iii)
(C) P-(iii), Q-(iv), R-(ii), S-(i)
(D) P-(iii), Q-(iv), R-(i), S-(ii)
Klinefelter syndrome, Down syndrome, Turner syndrome, and Cri du chat syndrome each link to specific chromosomal alterations. This matching question tests core genetics knowledge for exams like NEET. The correct option is (D) P-(iii), Q-(iv), R-(i), S-(ii).
Correct Matching
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P. Klinefelter syndrome pairs with (iii) 47, XXY, featuring an extra X chromosome in males, leading to tall stature, hypogonadism, and infertility.
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Q. Down syndrome matches (iv) Trisomy 21, caused by an extra chromosome 21, resulting in intellectual disability, characteristic facial features, and heart defects.
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R. Turner syndrome aligns with (i) 45, XO, a monosomy X condition in females causing short stature, webbed neck, and ovarian dysgenesis.
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S. Cri du chat syndrome corresponds to (ii) 5p minus, a deletion on the short arm of chromosome 5 producing a cat-like cry, microcephaly, and developmental delays.
Option Analysis
Option (A) incorrectly assigns Klinefelter to trisomy 21 and mixes others, ignoring sex chromosome specifics.
Option (B) wrongly links Down to 5p deletion and Klinefelter to it, confusing autosomal and sex-linked issues.
Option (C) swaps Cri du chat with Turner by assigning 5p minus to Turner, which has no deletion relation.
Option (D) accurately reflects standard karyotypes: 47,XXY for Klinefelter, trisomy 21 for Down, 45,XO for Turner, and 5p- for Cri du chat.
Exam Relevance
These pairings highlight aneuploidy and deletions in human genetics. Memorize karyotypes—47,XXY (Klinefelter), 47,XX/XY+21 (Down), 45,XO (Turner), del(5p) (Cri du chat)—for quick MCQ solving in biology exams.
