Find the correct statement for the prothallus of fern.

Options

A. Monoecious, protandrous with multicellular rhizoides
B. Monoecious, protandrous with unicellular rhizoides
C. Dioecious, with unicellular rhizoides
D. Monoecious, protandrous with apical antheredia, and basal archegonia on ventral surface

Answer

To find the correct statement regarding the prothallus of a fern, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Prothallus**:
- The prothallus is the gametophyte stage of a fern. It is a small, heart-shaped structure that is typically green and photosynthetic.

2. **Identify Characteristics**:
- The prothallus is **gametophytic** in nature, meaning it is involved in the production of gametes (sperm and eggs).
- It has **rhizoids**, which are root-like structures that help anchor the prothallus and absorb water and nutrients.

3. **Examine Options**:
- **Monoecious**: This means that both male and female gametes are produced on the same plant. In ferns, the prothallus is typically monoecious.
- **Protandrous**: This refers to a condition where the male gametes mature before the female gametes. Ferns often exhibit this characteristic.
- **Multicellular Rhizoids**: The rhizoids in the prothallus are usually unicellular, not multicellular.

4. **Evaluate Each Statement**:
- **Option 1**: Monoecious, protandrous, and multicellular rhizoids - The first two are correct, but the last part about rhizoids being multicellular is incorrect.
- **Option 2**: Monoecious, protandrous, and unicellular rhizoids - This option correctly describes the prothallus.
- **Option 3**: Dioecious with unicellular rhizoids - This is incorrect as dioecious means male and female are on different plants.
- **Option 4**: Monoecious, protandrous with apical antheridia - While monoecious and protandrous are correct, the term "apical" may not be universally applicable.

5. **Conclusion**:
- The correct statement for the prothallus of a fern is **Option 2**: Monoecious, protandrous, with unicellular rhizoids.