Suppose an organism has 5 pg of DNA in nucleus of its egg. How much DNA would a diploid cell has in its nucleus at `G_(1)` ?

Options

A. 5 pg
B. 10 pg
C. 20 pg
D. 2.5 pg

Explanation

To determine how much DNA a diploid cell has in its nucleus at the G1 phase, follow these steps:

### Step-by-Step Solution:

1. **Understand the DNA Content in the Egg**:
- The problem states that the organism has 5 picograms (pg) of DNA in the nucleus of its egg.

2. **Identify the Ploidy of the Egg**:
- The egg is haploid (1N), which means it contains one set of chromosomes. In this case, it has 5 pg of DNA.

3. **Determine the Ploidy of the Organism**:
- The organism is diploid (2N). This means it has two sets of chromosomes.

4. **Calculate the DNA Content in a Diploid Cell**:
- Since the diploid cell has two sets of chromosomes, the total amount of DNA in a diploid cell would be:
\[ \text{Total DNA in diploid cell} = 2 \times \text{DNA in haploid egg} = 2 \times 5 \text{ pg} = 10 \text{ pg} \]

5. **Consider the G1 Phase**:
- In the G1 phase of the cell cycle, the amount of DNA remains the same as in the diploid state because DNA replication has not yet occurred. Therefore, during G1, the diploid cell will still have 10 pg of DNA.

### Final Answer:
The amount of DNA in the nucleus of a diploid cell at the G1 phase is **10 picograms (pg)**.

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