Fusion of one of the male gametes with egg nucleus is referred to as

Options

A. generative fertilisation
B. syngamy
C. vegetative fertilisation
D. both (a) and (b)

Answer

To answer the question "Fusion of one of the male gametes with egg nucleus is referred to as," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Components**:
- In flowering plants, male gametes are produced in the pollen grain. The pollen grain consists of two types of cells: the generative cell and the vegetative cell.
- The generative cell divides to form two male gametes.

2. **Identifying the Process**:
- The process of fusion of one male gamete with the egg nucleus (which is part of the ovule) is a crucial step in fertilization.

3. **Defining the Terms**:
- **Syngamy**: This term specifically refers to the fusion of a male gamete with the egg nucleus.
- **Generative Fertilization**: This term can also refer to the same process, as it involves the generative cell's contribution to fertilization.

4. **Considering Other Options**:
- **Vegetative Fertilization**: This term refers to the fusion of the second male gamete with the central cell of the embryo sac, which is not the focus of the question.
- The option "both A and B" implies that both generative fertilization and syngamy are correct answers.

5. **Conclusion**:
- Since the fusion of one male gamete with the egg nucleus can be referred to as both generative fertilization and syngamy, the correct answer to the question is option four: "both A and B."

### Final Answer:
The fusion of one of the male gametes with the egg nucleus is referred to as both generative fertilization and syngamy (Option 4).

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