A fertilized egg of a plant has 40 chromosomes. The number of chromosomes present in the microspore mother cell is

Options

A. 20
B. 40
C. 60
D. 80

Explanation

To solve the problem, we need to determine the number of chromosomes present in the microspore mother cell, given that a fertilized egg of a plant has 40 chromosomes.

### Step-by-Step Solution:

1. **Understanding Chromosome Number**:
- The fertilized egg (zygote) of the plant has 40 chromosomes. This represents the diploid (2n) state of the organism, which means it contains two sets of chromosomes, one from each parent.

2. **Identifying the Ploidy Levels**:
- In plants, the microspore mother cell (also known as the pollen mother cell) is responsible for producing male gametes (pollen grains) through meiosis.
- The microspore mother cell is diploid (2n) and undergoes meiosis to produce haploid (n) microspores.

3. **Calculating the Number of Chromosomes in the Microspore Mother Cell**:
- Since the fertilized egg has 40 chromosomes (2n = 40), we can determine the haploid number (n) by dividing the diploid number by 2.
- Therefore, n = 40 / 2 = 20.
- This means that the number of chromosomes in the microspore mother cell (which is diploid) is also 20.

4. **Conclusion**:
- The number of chromosomes present in the microspore mother cell is 20.

### Final Answer:
The number of chromosomes present in the microspore mother cell is **20**.