Principles of Inheritance and Variation Question 163
163. Which one of the following conditions in humans. is correctly matched with its chromosomal abnormality/linkage?
[2008]
(a) Klinefelters syndrome-44 autosomes + XXY
(b) Colour blindness - Y-linked
(c) Erythroblastosis foetalis - X-linked
(d) Downs syndrome - 44 autosomes $+XO$
Show Answer
Answer : a
Hints & Solution
(a) Klinefelter’s syndrome is a genetic disorder affecting men in which an individual gains an extra $X$ chromosome, so that the usual karyotype of XY is replaced by XXY. Symptoms of Klinefelter’s syndrome named after U.S. physician H.P. Klinefelter, include female characteristics (such as breast enlargement).
