The number of chromosomes in the shoot tip cells of a maize plant is 20. The number of chromosomes in the microspore mother cells of the same plant shall be

Options

A. 20
B. 10
C. 40
D. 15

Explanation

To solve the question regarding the number of chromosomes in the microspore mother cells of a maize plant, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Ploidy Level of the Shoot Tip Cells:**
- The question states that the number of chromosomes in the shoot tip cells of a maize plant is 20.
- In plants, the shoot tip cells are typically diploid (2n), meaning they contain two sets of chromosomes.

2. **Understand the Chromosome Count:**
- Since the shoot tip cells are diploid and contain 20 chromosomes, we can denote this as:
- 2n = 20
- This indicates that the diploid number of chromosomes (2n) is 20.

3. **Determine the Ploidy Level of Microspore Mother Cells:**
- Microspore mother cells (also known as microsporocytes) are specialized cells that undergo meiosis to produce microspores, which eventually develop into pollen grains.
- Microspore mother cells are also diploid (2n) because they need to undergo meiosis to produce haploid (n) gametes.

4. **Conclusion on the Number of Chromosomes in Microspore Mother Cells:**
- Since microspore mother cells are diploid, they will have the same number of chromosomes as the shoot tip cells.
- Therefore, the number of chromosomes in the microspore mother cells of the maize plant is also 20.

### Final Answer:
The number of chromosomes in the microspore mother cells of the maize plant shall be **20 chromosomes**.

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