Pollen tube is made up of

Options

A. (a) cutin
B. (b) sporopollenin
C. (c) pectocellulose
D. (d) pectin

Answer

### Step-by-Step Solution:

1. **Understanding the Pollen Tube Formation**:
- The pollen tube is formed when a pollen grain germinates on the stigma of the female reproductive part of a flower. This process is initiated when the pollen grain lands on a compatible stigma.

2. **Components of the Pollen Grain**:
- A pollen grain consists of two nuclei: the generative nucleus and the vegetative nucleus. The generative nucleus divides to form two male gametes, while the vegetative nucleus develops into the pollen tube.

3. **Germination Process**:
- Upon germination on the stigma, the vegetative nucleus elongates and forms the pollen tube, which serves to transport the male gametes to the ovary for fertilization.

4. **Structure of the Pollen Tube**:
- The pollen tube has a cell wall that is composed of two layers:
- **Inner Layer**: Made up of callose.
- **Outer Layer**: Composed of pectin, cellulose, and hemicellulose.

5. **Identifying the Composition**:
- Among the options provided, we need to identify the correct composition of the pollen tube:
- **Option A**: Cutin - Incorrect, as cutin is found in cork tissue.
- **Option B**: Sporopollenin - Incorrect, as it is part of the outer layer of the pollen grain, not the pollen tube.
- **Option C**: Pectocellulose - Correct, as it includes both pectin and cellulose, which are components of the outer layer of the pollen tube.
- **Option D**: Pectin - While pectin is part of the composition, it does not encompass the full structure.

6. **Conclusion**:
- The most suitable answer regarding the composition of the pollen tube is **Option C: Pectocellulose**.