Absorption of ions by root hairs is

Options

A. Always active
B. Mostly active
C. Always passive
D. Mostly passive

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the mechanism of ion absorption by root hairs in plants.

2. **Role of Root Hairs**: Root hairs are specialized structures on the roots of plants that increase the surface area for absorption of water and nutrients from the soil.

3. **Absorption of Water**: Plants primarily absorb water from the soil through a process called osmosis. Osmosis is the movement of water molecules from an area of lower solute concentration to an area of higher solute concentration through a semi-permeable membrane.

4. **Absorption of Ions**: In addition to water, root hairs also absorb essential minerals and ions from the soil. This process is crucial for plant nutrition.

5. **Mechanism of Ion Absorption**: The absorption of ions by root hairs occurs mainly through active transport. Active transport is the process where ions are moved against their concentration gradient, which requires energy (usually in the form of ATP).

6. **Conclusion**: Given that the absorption of ions by root hairs is an active process that occurs against the concentration gradient, the correct answer to the question is that the absorption of ions by root hairs is "always active."

7. **Final Answer**: The correct option is **A) always active**.

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