Which of the following statements is correct?

Options

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

Answer

To determine which statement is correct among the provided options, we will analyze each statement one by one.

### Step 1: Analyze the first statement
**Statement:** "The stems are usually unbranched in both Cycus and Cedrus."
- **Cycus:** The stems are indeed erect and stout, and they are typically unbranched.
- **Cedrus:** However, Cedrus (the cedar tree) has branched stems.
- **Conclusion:** This statement is incorrect because while Cycus has unbranched stems, Cedrus does not.

### Step 2: Analyze the second statement
**Statement:** "Horsetails are Gymnosperms."
- **Horsetails:** Horsetails belong to the class of plants known as Pteridophytes, which are seedless vascular plants.
- **Gymnosperms:** Gymnosperms are seed-producing plants.
- **Conclusion:** This statement is incorrect because horsetails are not gymnosperms; they are seedless.

### Step 3: Analyze the third statement
**Statement:** "Selaginella is heterosporous while Salvinia is homosporous."
- **Selaginella:** This plant is indeed heterosporous, meaning it produces two different types of spores (microspores and macrospores).
- **Salvinia:** This plant is also heterosporous, not homosporous.
- **Conclusion:** This statement is incorrect because both Selaginella and Salvinia are heterosporous.

### Step 4: Analyze the fourth statement
**Statement:** "Ovules are not enclosed by the ovary wall in Gymnosperms."
- **Gymnosperms:** In gymnosperms, ovules are indeed not enclosed by an ovary wall; they are exposed on the surface of the cone.
- **Conclusion:** This statement is correct because it accurately describes the reproductive structure of gymnosperms.

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

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