Which of the following flowers is usually NOT used for the laboratory study of pollen germination ?

Options

A. Crotolaria
B. Vinca
C. Balsam
D. Cucumber

Answer

To solve the question regarding which flower is usually NOT used for the laboratory study of pollen germination, we can follow these steps:

### Step 1: Understand the Question
The question asks which flower is typically not utilized for studying pollen germination in a laboratory setting.

### Step 2: Analyze the Options
We have four options to consider:
- A) Crotalaria
- B) Cucumber
- C) Vinca
- D) Balsam

### Step 3: Evaluate Each Option
1. **Crotalaria**: This flower is known to be used for pollen germination studies.
2. **Cucumber**: The flowers of cucumber are sterile, meaning they do not produce viable pollen. Therefore, they cannot be used for studying pollen germination.
3. **Vinca**: This flower is also used for pollen germination studies.
4. **Balsam**: Similar to Vinca and Crotalaria, Balsam is used for studying pollen germination.

### Step 4: Conclusion
Based on the evaluations, the flower that is not used for the laboratory study of pollen germination is **Cucumber** (Option B).

### Final Answer
**B) Cucumber**

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