Select the correct statement. regarding the gymnosperms from the following .

Options

A. Gymnosperm are both homosporous and hetersporous.
B. Marsilea, Ginkgo and Pinus all are gymnosperms
C. The leaves of gymnosperms are not well adapted to extremes of climate.
D. The giant redwood tree Sequoia is one of the tallest tree species.

Answer

To solve the question regarding gymnosperms, we need to evaluate each of the provided statements and determine which one is correct.

### Step-by-Step Solution:

1. **Evaluate Statement 1**: "Gymnosperms are both homosporous and heterosporous."
- **Analysis**: Gymnosperms are primarily heterosporous, meaning they produce two different types of spores (microspores and megaspores). Homospory is more characteristic of certain other plant groups, such as many ferns. Therefore, this statement is incorrect.

**Hint**: Remember the difference between homosporous and heterosporous plants and their characteristics.

2. **Evaluate Statement 2**: "Marsilea, Ginkgo, and Pinus all are gymnosperms."
- **Analysis**: Ginkgo and Pinus are indeed gymnosperms. However, Marsilea is a genus of ferns and belongs to the pteridophytes, not gymnosperms. Thus, this statement is also incorrect.

**Hint**: Identify the classification of each plant mentioned to determine if they belong to gymnosperms.

3. **Evaluate Statement 3**: "Leaves of gymnosperms are not well adapted to extremes of temperature and climate."
- **Analysis**: This statement is incorrect. Gymnosperms, such as conifers, have leaves that are well adapted to extreme conditions, including cold climates. Their needle-like leaves and sunken stomata help reduce water loss and allow them to thrive in harsh environments.

**Hint**: Consider the adaptations of gymnosperm leaves to their environments.

4. **Evaluate Statement 4**: "The giant redwood sequoia tree is one of the tallest tree species."
- **Analysis**: This statement is correct. The giant redwood (Sequoiadendron giganteum) is indeed one of the tallest tree species in the world, with some individuals reaching heights of over 300 feet. Additionally, they can live for thousands of years.

**Hint**: Recall specific examples of tall trees and their characteristics.

### Conclusion:
After evaluating all four statements, the correct statement regarding gymnosperms is:

**Correct Answer**: The giant redwood sequoia tree is one of the tallest tree species.