Primary endosperm nucleus is formed by the fusion of _____ and_______

Options

A. Zygote and male gamete
B. Male gamete and embryo
C. Pollen grain and embryo
D. Secondary nuclie and male gamete

Answer

To answer the question, "Primary endosperm nucleus is formed by the fusion of _____ and_______," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Primary Endosperm Nucleus (PEN)**:
- The primary endosperm nucleus is abbreviated as PEN. It is a significant structure in the reproductive process of angiosperms (flowering plants).

2. **Concept of Triple Fusion**:
- The formation of the primary endosperm nucleus occurs through a process known as triple fusion. This involves the fusion of three nuclei.

3. **Identifying the Components Involved**:
- In the process of triple fusion, two polar nuclei (which are part of the embryo sac) fuse with one male gamete (sperm cell).

4. **Resulting Structure**:
- The fusion of these three nuclei results in a triploid structure (3N), which is the primary endosperm nucleus. This triploid structure is essential for the nourishment of the developing embryo.

5. **Conclusion**:
- Therefore, the primary endosperm nucleus is formed by the fusion of **two polar nuclei** and **one male gamete**.

### Final Answer:
The primary endosperm nucleus is formed by the fusion of **two polar nuclei** and **one male gamete**.

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