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: Understanding the Concept:
Cell division can be of two types: mitosis and meiosis. Mitosis produces two genetically identical diploid daughter cells. Meiosis is a special type of cell division that produces four haploid gametes (sperm and egg cells). Meiosis involves two rounds of division: Meiosis I and Meiosis II.
Step 2: Detailed Explanation:
- Mitosis: This is known as equational division because the daughter cells have the same number of chromosomes as the parent cell (2n $\rightarrow$ 2n).
- Meiosis I: This is the first meiotic division. During this stage, homologous chromosomes pair up and then separate, moving to opposite poles of the cell. This process reduces the chromosome number from diploid (2n) to haploid (n). Because the chromosome number is halved, Meiosis I is called reduction division.
- Mitosis I: This term is incorrect and does not exist in standard cell biology. Mitosis is a single process.
- Meiosis II: This is the second meiotic division. It is similar to mitosis. Sister chromatids separate, but the chromosome number does not change (it remains haploid). Therefore, Meiosis II is known as equational division.
Step 3: Final Answer:
Meiosis I is the stage where the number of chromosomes is reduced by half. Hence, it is known as reduction division.