NEETZoologyPrinciples of Inheritance and Variation
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Aneuploidy and polyploidy are two distinct categories of chromosomal anomalies with different cellular mechanisms. Reason (R): Aneuploidy arises due to the failure of cytokinesis after the telophase stage, whereas polyploidy arises due to the failure of segregation of chromatids during cell divisio
Options
- ABoth (A) and (R) are true and (R) is the correct explanation of (A)
- BBoth (A) and (R) are true but (R) is not the correct explanation of (A)
- C(A) is true but (R) is false
- D(A) is false but (R) is true
Correct answer
C. (A) is true but (R) is false
Step-by-step solution
The Assertion (A) is true because aneuploidy and polyploidy are indeed distinct chromosomal anomalies caused by different cellular errors. The Reason (R) is false because it incorrectly swaps the mechanisms. According to NCERT, aneuploidy arises due to the failure of segregation of chromatids during the cell division cycle, resulting in the gain or loss of a chromosome(s). On the other hand, polyploidy arises due to the failure of cytokinesis after the telophase stage of cell division, resulting in an increase in a