What are gemmules ?

Explanation

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

1. **Definition of Gemmules**: Gemmules are specialized structures that serve as a means of asexual reproduction in certain organisms, particularly sponges.

2. **Formation**: These structures are formed inside the body of some sponges. They appear as bud-like organs that develop under specific conditions.

3. **Function**: The primary function of gemmules is to ensure the survival of the organism during unfavorable environmental conditions. They can withstand extreme conditions such as drought or freezing temperatures.

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