All of the following are pre-fertilisation events except

Options

A. Spermatogenesis
B. Oogenesis
C. Gametes transfer
D. Embryogenesis

Answer

To solve the question "All of the following are pre-fertilization events except," we will analyze each option provided.

### Step-by-Step Solution:

1. **Understanding Pre-fertilization Events**:
- Pre-fertilization events are processes that occur before the fertilization of gametes. These include the formation and transfer of gametes.

2. **Analyzing the Options**:
- **Option 1: Spermatogenesis**:
- This is the process of forming sperm (male gametes). Since it occurs before fertilization, it is a pre-fertilization event.

- **Option 2: Oogenesis**:
- This is the process of forming eggs (female gametes). Like spermatogenesis, it occurs before fertilization, making it a pre-fertilization event as well.

- **Option 3: Gamete Transfer**:
- This involves the transfer of sperm to the egg for fertilization. Since this process occurs before fertilization, it is also a pre-fertilization event.

- **Option 4: Embryogenesis**:
- This is the process of development of the embryo after fertilization has occurred. Since it takes place after fertilization, it is not a pre-fertilization event.

3. **Conclusion**:
- The only option that is not a pre-fertilization event is **Embryogenesis**.

### Final Answer:
The correct answer is **Embryogenesis**.

---