Assertion :- It is believed particularly for some bryophytes and pteridophytes that their distribution is limited.
Reason :- They need water for transport of male gametes and fertilisation

Options

A. A
B. B
C. C
D. D

Answer

**Step-by-Step Solution:**

1. **Understanding the Assertion**: The assertion states that the distribution of some bryophytes and pteridophytes is limited. This is indeed correct because these plants typically thrive in moist environments where water is readily available.

2. **Understanding the Reason**: The reason provided is that bryophytes and pteridophytes need water for the transport of male gametes and fertilization. This is also correct. Male gametes in these plants are known as antherozoids, which are motile and require water to swim towards the non-motile egg cells for fertilization.

3. **Explaining Male Gamete Movement**: The male gametes (antherozoids) possess flagella, which allow them to swim. They need to reach the female reproductive structure, called archegonia, where the egg cell is located. The presence of water is crucial for this movement.

4. **Linking Assertion and Reason**: The limited distribution of bryophytes and pteridophytes can be directly linked to their dependence on water for fertilization. In areas where water is scarce, these plants cannot reproduce effectively, thus limiting their distribution.

5. **Conclusion**: Both the assertion and the reason are correct. The assertion about the limited distribution of bryophytes and pteridophytes is supported by the reason that they require water for the transport of male gametes and fertilization.

**Final Answer**: Both the assertion and the reason are correct, and the reason provided supports the assertion.

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