Question

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: Meiosis is a reductional division
Reason R: In meiosis, the chromosome number is reduced from diploid to haploid
In light of the above statements, choose the correct answer from the options given below:

• A. Both A and R are true and R is the correct explanation of A
• B. Both 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

Hint:

Remember that Meiosis I is the reductional division where homologous chromosomes separate, while Meiosis II is an equational division where sister chromatids separate, similar to mitosis.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Meiosis is a specialized form of cell division in sexually reproducing organisms that reduces the chromosome number in gametes, ensuring the preservation of the species-specific chromosome number across generations.

Step 2: Detailed Explanation:
Assertion A Analysis: In eukaryotic cell division, mitosis maintains a constant chromosome number (equational division), whereas meiosis reduces the chromosome number of the parent cell by half.
Because of this reduction, meiosis is referred to as reductional division. Thus, Assertion A is correct.
Reason R Analysis: During the first meiotic division (Meiosis I), homologous chromosomes pair up and subsequently segregate into different daughter cells.
This division reduces the chromosome number from diploid (\(2n\)) to haploid (\(n\)).
This reduction prevents the chromosome number from doubling with each successive generation upon fertilization. Thus, Reason R is correct.
Evaluating the Relationship: Meiosis is called a reductional division because it reduces the chromosome set from diploid to haploid.
Therefore, Reason R is a direct, accurate explanation of Assertion A.

Step 3: Final Answer:
Hence, both A and R are true and R is the correct explanation of A.