In a diploid cell before S-phase quantity of DNA is 20 pico gram (pg) after meiosis I what will be the quantity of DNA in each daughter cell ?

Options

A. 10 pg
B. 20 pg
C. 5 pg
D. 40 pg

Answer

To solve the problem, we need to understand the process of meiosis and how it affects the quantity of DNA in the daughter cells.

### Step-by-Step Solution:

1. **Understanding the Initial Condition:**
- We start with a diploid cell (2N) that has a DNA quantity of 20 picograms (pg). This means that before S-phase, the cell has 20 pg of DNA.

2. **DNA Replication During S-Phase:**
- During the S-phase of the cell cycle, the DNA is replicated. This means that the quantity of DNA doubles.
- Therefore, after the S-phase, the quantity of DNA in the cell becomes:
\[ 20 \, \text{pg} \times 2 = 40 \, \text{pg} \]

3. **Meiosis I:**
- Meiosis consists of two rounds of division: Meiosis I and Meiosis II.
- In Meiosis I, homologous chromosomes are separated. This means that the diploid cell (4N after S-phase) divides into two haploid cells (2N).

4. **Quantity of DNA After Meiosis I:**
- After Meiosis I, each daughter cell will receive half of the DNA content of the original cell. Since the original cell had 40 pg of DNA after S-phase, each daughter cell will have:
\[ \frac{40 \, \text{pg}}{2} = 20 \, \text{pg} \]

5. **Conclusion:**
- Therefore, after Meiosis I, the quantity of DNA in each daughter cell will be 20 picograms.

### Final Answer:
The quantity of DNA in each daughter cell after Meiosis I is **20 picograms**.

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