Which of the following is hetrosporous?

Options

A. Dryopteris
B. Salvinia
C. Adiantum
D. Equisetum

Answer

To determine which of the given plants is heterosporous, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Plants**: The plants given in the question are Dryobatrys, Salvinia, Adiantum, and Equisitum.

2. **Understand Heterospory**: Heterospory refers to the production of two different types of spores by the same plant. These spores are typically classified as:
- **Microspores**: Smaller spores that develop into male gametophytes.
- **Macrospores**: Larger spores that develop into female gametophytes.

3. **Classify the Plants**:
- **Pteridophytes**: All the mentioned plants (Dryobatrys, Salvinia, Adiantum, and Equisitum) belong to the group of Pteridophytes, which are vascular plants that reproduce via spores.
- **Homosporous vs. Heterosporous**: Most Pteridophytes are homosporous, meaning they produce only one type of spore. However, some are heterosporous.

4. **Check Each Plant**:
- **Dryobatrys**: This plant is homosporous.
- **Salvinia**: This plant is heterosporous, producing both microspores and macrospores.
- **Adiantum**: This plant is also homosporous.
- **Equisetum**: This plant is generally homosporous.

5. **Conclusion**: Based on the classification, Salvinia is the only plant among the options that is heterosporous.

### Final Answer:
The heterosporous plant among the given options is **Salvinia**.

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