Bisexual flowers which never open, demonstrate

Options

A. Homogamous
B. Heterogamous
C. Dichogamous
D. Cleistogamous.

Answer

**Step-by-Step Text Solution:**

1. **Understanding the Question:**
The question asks about bisexual flowers that never open and what type of pollination they demonstrate.

2. **Identifying Types of Pollination:**
There are two main types of pollination to consider:
- Autogamy (self-pollination)
- Cross-pollination (which includes various forms like dichogamy).

3. **Defining Autogamy:**
Autogamy refers to self-pollination, which occurs when pollen from the male part of a flower fertilizes the female part of the same flower. For this to happen, the flower must be bisexual, containing both stamens (male) and carpels (female).

4. **Types of Bisexual Flowers:**
- **Chasmogamous Flowers:** These are open bisexual flowers that can undergo autogamy.
- **Clistogamous Flowers:** These are closed bisexual flowers that never open and are exclusively self-pollinating.

5. **Characteristics of Clistogamous Flowers:**
- Clistogamous flowers are always bisexual and do not open.
- They ensure 100% seed setting without the need for pollinating agents (like insects or wind).
- Examples of clistogamous flowers include Camelina, Viola, and Oxalis.

6. **Implications of Self-Pollination:**
While clistogamous flowers guarantee seed production, they can lead to inbreeding depression over time due to lack of genetic diversity.

7. **Conclusion:**
Based on the definitions and characteristics discussed, the type of pollination demonstrated by bisexual flowers that never open is **clistogamy**.

8. **Final Answer:**
The correct answer is clistogamy.

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