The pollen tubes grow through the solid style by separating their cell through the secretion of

Options

A. (a) lipase
B. (b) protease
C. (c) amylase
D. (d) pectinase

Answer

**Step-by-Step Solution:**

1. **Understanding the Structure**: The question refers to the pollen tube's growth through the style, which is part of the carpel in flowering plants. The carpel consists of three main parts: the stigma, style, and ovary.

2. **Role of the Pollen Tube**: The pollen tube grows from the pollen grain after it lands on the stigma. It travels down the style to reach the ovary, where fertilization occurs.

3. **Secretion of Enzymes**: As the pollen tube grows, it needs to penetrate the solid structure of the style. To do this, it secretes specific enzymes that help break down the cell walls of the style.

4. **Identifying the Correct Enzyme**: The main component of the cell walls in the carpel is pectin. Therefore, the pollen tube secretes pectinases, enzymes that specifically degrade pectin, allowing the pollen tube to separate the cells and grow through the style towards the ovary.

5. **Evaluating Other Options**:
- **Lipases**: These enzymes break down lipids, which are not the primary components of the cell walls in the style.
- **Proteases**: These enzymes degrade proteins, which are also not the main components of the cell walls in this context.
- **Amylase**: This enzyme breaks down carbohydrates, but since pectin is the most abundant component, amylase is not suitable.

6. **Conclusion**: Since pectin is the major component of the cell wall in the style, the correct answer is that the pollen tube secretes pectinases to facilitate its growth through the style.

**Final Answer**: The pollen tubes grow through the solid style by separating their cells through the secretion of **pectinases**.

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