If a wrong type of pollen or pollen from a different species lands on the stigma, which of these in NOT formed?

Options

A. egg cell
B. embryo
C. embryo sac
D. (all of the above will be formed)

Answer

To answer the question, "If a wrong type of pollen or pollen from a different species lands on the stigma, which of these is NOT formed?", we need to understand the process of fertilization and the role of pollen in plant reproduction.

### Step-by-Step Solution:

1. **Understanding Pollen and Stigma**:
- Pollen grains are the male gametes in plants. They must land on the stigma of the same species for successful fertilization to occur.
- If pollen from a different species lands on the stigma, it typically cannot fertilize the ovule.

**Hint**: Remember that successful fertilization requires compatibility between the pollen and the stigma.

2. **Consequences of Wrong Pollen**:
- When incompatible pollen lands on the stigma, it does not lead to fertilization. This means that the male gamete cannot unite with the female gamete (egg cell).
- Without fertilization, the development of an embryo cannot take place.

**Hint**: Think about the relationship between fertilization and embryo development.

3. **Formation of Structures**:
- The egg cell is formed in the ovary before pollination occurs, so its formation is not affected by the type of pollen.
- The embryo sac, which houses the egg cell, is also formed prior to pollination and is not directly affected by the type of pollen that lands on the stigma.

**Hint**: Consider which structures are formed before and after pollination.

4. **Conclusion**:
- Since the question asks which structure is NOT formed when wrong pollen lands on the stigma, the answer is the **embryo**. The embryo can only form if fertilization occurs, which does not happen with incompatible pollen.

### Final Answer:
The structure that is NOT formed when a wrong type of pollen lands on the stigma is the **embryo**.