Which of the following statements is correct

Options

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

Answer

To determine which of the statements is correct, let's analyze each option step by step.

### Step-by-Step Solution:

1. **Analyzing the First Statement:**
- **Statement:** "Selaginella is heterosporous while Salvinia is homosporous."
- **Explanation:**
- Heterosporous plants produce two types of spores (microspores and megaspores), while homosporous plants produce only one type of spore.
- Both Selaginella and Salvinia are actually heterosporous.
- **Conclusion:** This statement is **incorrect**.

2. **Analyzing the Second Statement:**
- **Statement:** "Horsetails are Gymnosperms."
- **Explanation:**
- Horsetails (Equisetum) are vascular plants that reproduce via spores and are classified under the group of ferns, not gymnosperms.
- **Conclusion:** This statement is **incorrect**.

3. **Analyzing the Third Statement:**
- **Statement:** "Ovules are not enclosed by ovary walls in Gymnosperms."
- **Explanation:**
- Gymnosperms are known as "naked seed" plants, meaning their ovules are not enclosed by ovary walls.
- **Conclusion:** This statement is **correct**.

4. **Analyzing the Fourth Statement:**
- **Statement:** "Stems are usually unbranched in both Cycus and Cedrus."
- **Explanation:**
- Cycus (Cycad) typically has an unbranched stem, while Cedrus (Cedar) usually has a branched stem.
- **Conclusion:** This statement is **incorrect**.

### Final Conclusion:
The only correct statement among the options provided is:
- **"Ovules are not enclosed by ovary walls in Gymnosperms."**