Question

Assertion :Down's syndrome, Klinfelter's syndrome and Turner's syndrome are chromosomal disorders. Reason: In Klinfelter syndrome females are sterile.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is C Assertion is correct but Reason is incorrect

• Change in the number or structure of chromosomes results in chromosomal disorders.
• Klinefelter's syndrome, also known as 47.XXY or XXY is the set of symptoms that result from two or more X chromosomes in males. The primary features are infertility and small testicles.
• Down's syndrome is caused by having three copies of chromosome 21 (trisomy 21) instead of the usual two copies. It is associated with intellectual disability, a characteristic facial appearance, with a small nose and an upward slant to the eyes, and low muscle tone in infancy.
  
• Turner's syndrome is a chromosomal disorder that affects development in females. It results when a female's cells have only one normal X chromosome and the other sex chromosome is either missing or structurally altered.
  
• So, the correct answer is 'Assertion is correct but Reason is incorrect'