Question

Assertion (A) Down’s syndrome is a Mendelian disorder.
Reason (R) It is caused due to the presence of an additional copy of chromosome $21$.

• A. If both A and R are true and R is the correct explanation of A
• B. If both A and R are true, but R is not the correct explanation of A
• C. If A is true, but R is false
• D. If A is false, but R is true

Answer 1

Answer: (D)

Assertion is false, but Reason is true. Assertion can be corrected as
Down’s syndrome is a chromosomal disorder. It is caused due to the presence of an additional copy chromosome $21$ (trisomy $21$).