The phenomenon observed in some plants wherein parts of the sexual apparatus is used for forming embryos without fertilisation is called

Options

A. parthenocarpy
B. apomixis
C. vegetative propagation
D. sexual reproduction

Explanation

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about a specific phenomenon in plants where parts of the sexual apparatus are used to form embryos without the process of fertilization.

2. **Identifying the Sexual Apparatus**: In flowering plants, the sexual apparatus primarily consists of the male and female reproductive parts. The female reproductive part is known as the pistil, which includes the ovary, style, and stigma.

3. **Defining the Key Term**: The phenomenon of forming embryos without fertilization is known as **apomixis**. This term is derived from Greek, where "apo" means away and "mixis" refers to mixing, indicating that there is no mixing of male and female gametes involved in this process.

4. **Explaining Apomixis**: In apomixis, the development of the embryo occurs directly from the megaspore mother cell (2n) without fertilization. The megaspore mother cell undergoes a process that leads to the formation of a megaspore, which can also be diploid (2n). This megaspore then develops directly into an embryo, resulting in the formation of seeds without the need for fertilization by male gametes.

5. **Conclusion**: Therefore, the phenomenon observed in some plants wherein parts of the sexual apparatus are used for forming embryos without fertilization is called **apomixis**.