Gemmules are formed in

Options

A. all sponges
B. All freshwater sponges
C. Some marine sponges
D. All of these

Answer

**Step-by-Step Text Solution:**

1. **Understanding Gemmules**:
- Gemmules are internal buds formed by sponges. They are a form of asexual reproduction.

2. **Identifying the Organisms**:
- Gemmules are specifically produced by certain species of sponges.

3. **Types of Sponges**:
- There are freshwater sponges and marine sponges.
- Some freshwater sponges, such as those from the genus *Spongilla*, produce gemmules.
- Certain marine sponges, like *Fissidens ficus*, also produce gemmules.

4. **Purpose of Gemmules**:
- Gemmules serve as a survival mechanism for sponges during unfavorable environmental conditions.
- They can germinate to produce new sponges when conditions become favorable.

5. **Analyzing the Options**:
- Option A: "All sponges" - Incorrect, as not all sponges produce gemmules.
- Option B: "All freshwater sponges" - Incorrect, as only some freshwater sponges produce gemmules.
- Option C: "Some marine sponges" - Correct, as some marine sponges do produce gemmules.
- Option D: "All of these" - Incorrect, as not all mentioned groups produce gemmules.

6. **Conclusion**:
- The correct answer is **C: Some marine sponges**.

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