Find out the number of chromosomes and the amount of DNA in a spore mother cell of Bryophytes in `G_(2)` stage (If the spore contains 5 chromosomes and 5pg of DNA) -

Options

A. 5 Chromosome, 5pg DNA
B. 10 Chromosome, 20pg DNA
C. 10 Chromosome, 10pg DNA
D. 20 Chromosomes, 20pg DNA

Answer

To solve the problem, we need to analyze the information given about the spore mother cell of Bryophytes in the G2 stage.

### Step-by-Step Solution:

1. **Understanding the Spore Characteristics**:
- The question states that the spore contains 5 chromosomes and 5 picograms (pg) of DNA.
- Spores in Bryophytes are haploid (n), meaning they have a single set of chromosomes.

2. **Determining the Spore Mother Cell Characteristics**:
- The spore mother cell (also known as the sporophyte or microsporocyte in Bryophytes) is diploid (2n).
- Therefore, if the spore is haploid with 5 chromosomes, the spore mother cell will have double the number of chromosomes.

3. **Calculating Chromosome Number**:
- Since the spore has 5 chromosomes (n = 5), the spore mother cell will have:
\[ \text{Number of chromosomes in spore mother cell} = 2n = 2 \times 5 = 10 \text{ chromosomes} \]

4. **Calculating the Amount of DNA**:
- The amount of DNA in the spore is given as 5 pg.
- In the G2 phase of the cell cycle, the DNA content has doubled compared to the G1 phase. Hence, the amount of DNA in the spore mother cell will also be double that of the spore:
\[ \text{Amount of DNA in spore mother cell} = 2 \times 5 \text{ pg} = 10 \text{ pg} \]

5. **Final Result**:
- Therefore, in the G2 stage, the spore mother cell of Bryophytes has:
- **10 chromosomes**
- **10 picograms of DNA**

### Conclusion:
The answer is:
- **10 chromosomes and 10 pg of DNA**.