Principles of Inheritance and Variation Question 138

138. In which genetic condition, each cell in the affected person, has three sex chromosomes XXY?

[2019, Odisha]

(a) Turner’s syndrome

(b) Thalassemia

(c) Klinefelter’s syndrome

(d) Phenylketonuria

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Answer : c

Hints & Solution

(c) Klinefelter’s syndrome is a chromosomal conditions in boys and men that can affect physical and intellectual development. It is caused due to presence of an additional copy of X-chromosome resulting into $44+XXY$ type chromosome complement. Adult with this syndrome may have primary hypogonadism (decreased testosterone production), small or underscent testes, enlarged breast, tall stature etc. Klinefelter syndrome isn’t passed down through families like some genetic diseases. Instead, it happens randomly from an error in cell division when a parent’s reproductive cells are being formed and occurs only as a result of a random genetic error after conception. Most males with this condition produce little or no sperm. Its Treatment may include testosterone replacement and fertility treatment.



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