If the egg of an organism has 10 Pg of DNA in its nucleus, how much DNA would a diploid cell of same organism have in G2-phase of Meiosis

Options

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

Answer

To solve the question, we need to determine how much DNA a diploid cell of the same organism would have in the G2 phase of meiosis, given that the egg (which is a haploid cell) has 10 picograms (Pg) of DNA.

### Step-by-Step Solution:

1. **Understand the DNA content in the egg**: The question states that the egg of the organism has 10 Pg of DNA. Since the egg is a haploid cell, we denote its DNA content as "N". Therefore, N = 10 Pg.

2. **Determine the diploid DNA content**: A diploid cell contains two sets of chromosomes, which means it has double the amount of DNA compared to a haploid cell. We denote the diploid DNA content as "2N". Thus, the DNA content in a diploid cell would be:
\[ 2N = 2 \times 10 \text{ Pg} = 20 \text{ Pg} \]

3. **Identify the G2 phase of the cell cycle**: The G2 phase is the stage in the cell cycle after DNA replication has occurred. During the S phase of the cell cycle, the DNA content of the cell doubles. Therefore, if we start with 20 Pg of DNA in the diploid cell (2N), after the S phase, the DNA content will double.

4. **Calculate the DNA content in G2 phase**: Since the diploid cell has 20 Pg of DNA before the S phase, after DNA replication in the S phase, the amount of DNA in the G2 phase will be:
\[ \text{DNA in G2} = 2 \times 20 \text{ Pg} = 40 \text{ Pg} \]

5. **Final Answer**: Therefore, the amount of DNA in the diploid cell of the same organism in the G2 phase of meiosis is **40 Pg**.