Several pollen grains form a unit designated as pollinium in Family

Options

A. Asteraceae
B. Cucuribitaceae
C. Asclepiadaceae
D. Brassicaceae

Explanation

To solve the question regarding which family has several pollen grains that form a unit designated as pollinium, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Pollinium**:
- A pollinium is a structure that consists of multiple pollen grains that are fused together to function as a single unit. This is important for the process of pollination.

2. **Identify the Families Listed in the Options**:
- The options provided are:
- A) Asteraceae
- B) Cucurbitaceae
- C) Asclepiadaceae
- D) Brassicaceae

3. **Analyze Each Family**:
- **Asteraceae**: Known as the daisy family, it does not typically form pollinia.
- **Cucurbitaceae**: Includes plants like squash and cucumber, which also do not form pollinia.
- **Asclepiadaceae**: This family includes orchids and plants like Calotropis, which are known to produce pollinia.
- **Brassicaceae**: This family includes cabbage and radish, which do not produce pollinia.

4. **Determine the Correct Answer**:
- Based on the analysis, the family that forms a unit of several pollen grains designated as pollinium is **Asclepiadaceae**.

5. **Final Answer**:
- The correct answer is **C) Asclepiadaceae**.