What is true about cleistogamy?

Options

A. It occurs in unisexual flowers
B. It produces assured seed-set even in the absence of pollinators
C. it leads to introduction of new useful characters
D. It is a method of geitonogamy

Explanation

### Step-by-Step Solution:

1. **Understanding Cleistogamy**: Cleistogamy refers to a type of reproduction in flowering plants where flowers remain closed and self-pollinate without opening. This process typically occurs in bisexual flowers, which contain both male (stamens) and female (pistils) reproductive structures.

2. **Analyzing the Options**:
- **Option A: It occurs in unisexual flowers**: This statement is incorrect. Cleistogamy occurs in bisexual flowers, not unisexual ones.
- **Option B: It produces a short seed set even in the absence of pollinators**: This statement is correct. Since cleistogamous flowers self-pollinate, they can produce seeds without the need for pollinators.
- **Option C: It leads to the introduction of new useful characters**: This statement is incorrect. Cleistogamy results in self-pollination, which does not introduce genetic variation or new characters, as there is no cross-pollination involved.
- **Option D: It is a method of Getanogamy**: This statement is incorrect. Getanogamy refers to cross-pollination, which is the opposite of what occurs in cleistogamy.

3. **Conclusion**: The only true statement about cleistogamy is that it produces a short seed set even in the absence of pollinators (Option B).

### Final Answer:
The true statement about cleistogamy is that it produces a short seed set even in the absence of pollinators.

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