MarksRiser
MarksRiser
RE-NEET2026Botany-Genetics

RE-NEET 2026 Botany Chromosomal Disorders Assertion Reason Question

Type: Assertion Reason-conceptual-Medium-Class 12

Given below are two statements:

Statement I: Down's syndrome is caused by the absence of one of the X-chromosomes.

Statement II: Turner's syndrome is caused by the presence of an additional copy of the chromosomes.

In the light of the above statements, choose the correct answer from the options given below:

A

Both Statement I and Statement II are incorrect

B

Statement I is correct but Statement II is incorrect

C

Statement I is incorrect but Statement II is correct

D

Both Statement I and Statement II are correct

Correct Answer

Option A

Detailed Explanation

Both statements are incorrect. Down's syndrome is caused by an extra copy of chromosome 21 (trisomy 21), not the absence of an X chromosome. In contrast, Turner's syndrome results from the absence of one X chromosome (45,X), not from the presence of an additional chromosome.

Thus, the correct answer is A) Both Statement I and Statement II are incorrect.

The tempting wrong options fail because they misattribute the causes of these syndromes: Statement I incorrectly describes Down's syndrome, while Statement II incorrectly describes Turner's syndrome.

Found an issue with this question?