How many nuclei are present in a mature pollen?

Options

A. 1
B. 7
C. 3
D. 4

Answer

To determine how many nuclei are present in a mature pollen grain, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of Pollen Grain**: A mature pollen grain consists of two main cells: the vegetative cell and the generative cell.

2. **Identify the Nuclei in Each Cell**:
- The **vegetative cell** contains **one nucleus**. This nucleus is referred to as the tube nucleus, which is responsible for forming the pollen tube during fertilization.
- The **generative cell** initially contains **one nucleus**. However, this nucleus will undergo division.

3. **Division of the Generative Cell**:
- The generative nucleus divides to form **two sperm nuclei**. This means that after division, the generative cell contributes two additional nuclei.

4. **Count the Total Nuclei**:
- From the vegetative cell, we have **1 tube nucleus**.
- From the generative cell, after division, we have **2 sperm nuclei**.
- Therefore, the total number of nuclei in a mature pollen grain is:
- 1 (tube nucleus) + 2 (sperm nuclei) = **3 nuclei**.

5. **Conclusion**: The final answer is that a mature pollen grain contains a total of **3 nuclei**.

### Final Answer:
A mature pollen grain contains **3 nuclei**: 1 tube nucleus and 2 sperm nuclei.

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