An event unique to flowering plants is :

Options

A. True fertilisation
B. Double fertilisation
C. Embryogenesis
D. Pollination

Answer

**Step-by-Step Solution:**

1. **Identify the Unique Event**: The question asks for an event that is unique to flowering plants, also known as angiosperms. The key term to focus on is "unique" to flowering plants.

2. **Recognize Double Fertilization**: The unique event associated with flowering plants is double fertilization. This is a characteristic feature of angiosperms that distinguishes them from other plant groups.

3. **Understand the Process of Double Fertilization**:
- **Syngamy**: This is the first part of double fertilization where one male gamete from the pollen tube fuses with the egg cell in the embryo sac, resulting in the formation of a zygote. The zygote is diploid (2n).
- **Triple Fusion**: The second male gamete fuses with the two polar nuclei present in the central cell of the embryo sac, leading to the formation of a triploid (3n) primary endosperm cell, which will develop into the endosperm that nourishes the developing embryo.

4. **Conclusion**: Since double fertilization consists of both syngamy and triple fusion, it is the defining reproductive event that is unique to flowering plants. Therefore, the correct answer to the question is option number 2: double fertilization.

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