Among the following which structure is not functionally similar to others

Options

A. Archegonium
B. Antheridium
C. Oogonium
D. Ovum

Answer

To determine which structure is not functionally similar to the others among Archegonium, Antheridium, Oogonium, and Ovum, we can analyze each option step by step.

### Step-by-Step Solution:

1. **Identify the Structures**:
- **Archegonium**: This is the female reproductive organ found in lower plants like bryophytes and pteridophytes. It produces a single egg.
- **Antheridium**: This is the male reproductive organ that produces male gametes known as antherozoids.
- **Oogonium**: This is also a female reproductive organ found in certain algae, producing female gametes.
- **Ovum**: This is the female gamete itself.

2. **Classify the Structures**:
- **Female Structures**: Archegonium and Oogonium are both female sex organs. The Ovum is a female gamete.
- **Male Structure**: Antheridium is the male sex organ.

3. **Determine Functional Similarity**:
- Archegonium, Oogonium, and Ovum are all related to the female reproductive process.
- Antheridium is related to the male reproductive process.

4. **Conclusion**:
- Since Antheridium is the only male reproductive structure among the options, it is not functionally similar to the others, which are all involved in female reproduction.

### Final Answer:
The structure that is not functionally similar to the others is **Antheridium**.