Cork cells are made impervious to water and gases by the presence of

Options

A. cellulose
B. lipids
C. suberin
D. lignin

Explanation

**Step-by-Step Solution:**

1. **Understanding Cork Cells**: Cork cells are specialized cells found in the outer layer of bark in plants. They play a crucial role in protecting the plant and preventing water loss.

2. **Identifying Cell Membranes**: Plant cells are enclosed by two membranes: the cell membrane (plasma membrane) and the cell wall. The plasma membrane is semi-permeable, allowing some substances to pass through.

3. **Role of Cell Wall**: The cell wall, primarily made of cellulose, is generally permeable to water and gases. Therefore, cellulose alone does not make cork cells impervious to water and gases.

4. **Evaluating Other Options**:
- **Lipids**: While lipids are important in cell membranes, they do not contribute to the impermeability of cork cells.
- **Lignin**: Although lignin is a strong polymer found in some plant cells (like sclerenchyma), it is not present in cork cells.

5. **Identifying the Correct Substance**: The substance that makes cork cells impervious to water and gases is **suberine**. Suberine is a special organic compound found in the cell walls of cork cells, providing them with their waterproof characteristics.

6. **Conclusion**: Therefore, the correct answer is that cork cells are made impervious to water and gases by the presence of **suberine**.

---