Question

Which of the following is also known as reduction division?

• A. Mitosis
• B. Meiosis I
• C. Mitosis I
• D. Meiosis II

Hint:

Remember: {Meiosis I = Reductional} (reduces chromosome number from 2n to n). {Meiosis II = Equational} (like mitosis, separates sister chromatids, n to n).

Answer 1

The Correct Option is B

Step 1: Introduction:
Cell division occurs via mitosis or meiosis. Mitosis yields two identical diploid (2n) cells. Meiosis, a specialized process, produces four haploid (n) gametes (sperm and egg). Meiosis comprises two sequential divisions: Meiosis I and Meiosis II.
Step 2: Detailed Breakdown:
- Mitosis: An equational division where daughter cells retain the parent cell's chromosome number (2n $\rightarrow$ 2n).
- Meiosis I: The first meiotic division. Homologous chromosomes pair and separate, migrating to opposite poles. This halves the chromosome number from diploid (2n) to haploid (n). Meiosis I is termed reduction division due to this chromosome reduction.
- Mitosis I: This is not a valid term. Mitosis is a single, continuous process.
- Meiosis II: The second meiotic division, resembling mitosis. Sister chromatids separate, but the chromosome number remains haploid (n). Meiosis II is therefore considered an equational division.
Step 3: Conclusion:
Meiosis I reduces the chromosome number by half and is therefore called reduction division.