Doubles fertilization is fusion of

Options

A. one egg with two sperms
B. sperm nucleus with egg nucleus as well as with polar nuclei
C. one male gamete with egg and other male gamete with synergid
D. one male gamete with egg with other male gamete with secondary nucleus

Answer

**Step-by-Step Solution:**

1. **Understanding Double Fertilization**:
- Double fertilization is a unique process that occurs in angiosperms (flowering plants). It involves two distinct fusion events during the fertilization process.

2. **Pollen Grain Structure**:
- A pollen grain consists of three cells: one vegetative cell and two male gametes. The vegetative cell forms the pollen tube, while the male gametes are involved in fertilization.

3. **Pollen Tube Germination**:
- When the pollen grain lands on the stigma of a flower, it germinates and forms a pollen tube that grows down into the ovary and into the ovule.

4. **Entering the Embryo Sac**:
- The pollen tube enters the ovule and reaches the embryo sac, which contains the egg cell and the central cell (which has two polar nuclei).

5. **Fusion Events**:
- The first male gamete fuses with the egg cell to form the zygote. This fusion is termed **syngamy**.
- The second male gamete fuses with the central cell (which contains two polar nuclei) to form a primary endosperm cell. This fusion is termed **triple fusion**.

6. **Result of Double Fertilization**:
- The result of double fertilization is the formation of:
- A zygote (from syngamy) which will develop into the embryo.
- A primary endosperm cell (from triple fusion) which will develop into the endosperm, providing nourishment to the developing embryo.

7. **Conclusion**:
- Therefore, double fertilization involves the fusion of one male gamete with the egg cell and the other male gamete with the central cell (polar nuclei).

**Final Answer**: Double fertilization is the fusion of one male gamete with the egg cell and the other male gamete with the central cell (polar nuclei).

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