Which of the following statements is correct?

Options

A. Ovules are not enclosed by ovary wall in gymnosperms
B. Stems are usually unbranched in both Cycas and Cedrus
C. Horsetails are gymnosperms
D. Selaginella is heterosporous, while Salvinia is homosporous

Answer

To solve the question, "Which of the following statements is correct?", we will analyze each of the four statements provided and determine which one is accurate.

### Step-by-Step Solution:

1. **Analyze the First Statement**:
- The statement says, "Ovules are not enclosed by every wall in gymnosperm."
- In gymnosperms, ovules are indeed not enclosed by an ovary wall; they are referred to as "naked seeds." This is because gymnosperms lack ovaries, which means that the ovules are exposed before fertilization.
- **Conclusion**: This statement is correct.

2. **Analyze the Second Statement**:
- The statement claims, "Stems are usually unbranched in both Cycus and Sidrus."
- Cycus (Cycad) typically has an unbranched stem, but Sidrus (Cedrus) is known to have a branched stem.
- **Conclusion**: This statement is incorrect.

3. **Analyze the Third Statement**:
- The statement states, "Horsetails are gymnosperms."
- Horsetails are actually classified as pteridophytes, not gymnosperms.
- **Conclusion**: This statement is incorrect.

4. **Analyze the Fourth Statement**:
- The statement says, "Syllaginella is heterosporous while Selvenia is homosporous."
- Syllaginella (Selaginella) is indeed heterosporous, but Selvenia (Selaginella) is also heterosporous, not homosporous.
- **Conclusion**: This statement is incorrect.

### Final Conclusion:
After analyzing all the statements, the only correct statement is the first one: "Ovules are not enclosed by every wall in gymnosperm."