The spread of living pteridophytes is limited and is restricted to narrow geographical region because

Options

A. gametophytic growth needs cool, damp and shadyy places
B. there is requirement of water for fertilisation
C. there is absence of stomata in leaf and absence of vascular tissue
D. both a and b

Answer

**Step-by-Step Solution:**

1. **Understanding Pteridophytes**: Pteridophytes are a group of vascular plants that reproduce via spores and do not produce seeds. They include ferns, horsetails, and clubmosses.

2. **Gametophyte Stage**: In the life cycle of pteridophytes, there is a dominant sporophyte stage and a smaller gametophyte stage. The gametophyte is usually a small, heart-shaped structure that is dependent on the sporophyte for nutrition.

3. **Environmental Requirements**: The gametophyte of pteridophytes requires specific environmental conditions for growth. It thrives in cool, damp, and shady places. This is essential for its survival and development.

4. **Water Requirement for Fertilization**: Fertilization in pteridophytes involves the movement of sperm to the egg, which requires water. The sperm are motile and swim through water to reach the egg, making the presence of water crucial for reproduction.

5. **Geographical Limitation**: Due to the specific requirements of the gametophyte for cool, damp, and shady environments, along with the necessity of water for fertilization, pteridophytes are limited in their geographical distribution. They are typically found in regions that meet these environmental conditions, which are not widespread.

6. **Evaluating the Options**:
- Option 1 states that gametophytic growth needs cool, damp, and shady places (True).
- Option 2 states there is a requirement of water for fertilization (True).
- Option 3 mentions the absence of stomata and vascular tissue, which is not a reason for geographical limitation (False).
- Option 4 combines options 1 and 2, which are both correct.

7. **Conclusion**: Therefore, the correct answer is option 4, which states that both A and B are correct. The spread of living pteridophytes is limited due to their specific environmental needs and the requirement of water for fertilization.

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