Prothallus is

Options

A. small, multicellular, free living, photosynthetic thalloid sporophyte
B. small, multicellular, free living, photosynthetic gametophyte
C. large, multicellular, free-living, photosynthetic thalloid gametophyte
D. large, multicellular, free living, non photosynthetic sporophyte

Answer

To answer the question "What is Prothallus?", we can break down the information as follows:

### Step-by-Step Solution:

1. **Definition of Prothallus**: Prothallus is a structure found in certain plants, specifically in the group known as pteridophytes (ferns and their relatives).

2. **Type of Structure**: It is classified as a gametophytic structure. This means it is involved in the gamete production (sperm and eggs) in the plant life cycle.

3. **Size of Prothallus**: Prothallus is generally small in size, typically measuring between 3 to 10 mm in length and 2 to 8 mm in breadth.

4. **Characteristics of Prothallus**:
- It is multicellular, meaning it is composed of more than one cell.
- It is free-living, which indicates that it does not depend on the sporophyte for survival.
- It is photosynthetic, allowing it to produce its own food through the process of photosynthesis.

5. **Conclusion**: Based on the characteristics outlined, Prothallus can be described as a small, multicellular, free-living, photosynthetic gametophyte.

### Final Answer:
Prothallus is a small, multicellular, free-living photosynthetic gametophyte found in pteridophytes.

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