During meiosis how cycles of nucleus division, DNA replication and division of centromere take place respectively :-

Options

A. Three, Two, One
B. One, Two, Two
C. Two, Two, One
D. Two, One, One

Answer

To answer the question regarding the cycles of nucleus division, DNA replication, and division of centromeres during meiosis, we can break it down step by step:

### Step-by-Step Solution:

1. **Understanding Nuclear Division:**
- Meiosis involves two rounds of nuclear division known as karyokinesis.
- The first nuclear division occurs during **Meiosis I**, and the second nuclear division occurs during **Meiosis II**.
- Therefore, the total number of nuclear divisions during meiosis is **2 times**.

2. **Understanding DNA Replication:**
- DNA replication occurs during the **S phase** of the cell cycle.
- In meiosis, DNA replication happens only **once** before the cell enters the meiotic phase.
- Thus, the total number of DNA replications during meiosis is **1 time**.

3. **Understanding Division of Centromeres:**
- The division of centromeres occurs during **anaphase**, when sister chromatids are pulled apart.
- In meiosis, there are two anaphases: **anaphase I** and **anaphase II**.
- However, centromere division does not occur during anaphase I because homologous chromosomes separate, but the sister chromatids remain attached at their centromeres.
- Centromere division occurs during **anaphase II** when the sister chromatids are separated.
- Therefore, the total number of centromere divisions during meiosis is **1 time**.

### Final Answer:
- Nuclear division: **2 times**
- DNA replication: **1 time**
- Division of centromere: **1 time**