Minerals enter a plant mainly by
(a) diffusion
(b) pressure flow
(c) translocation
(d) active transport

Options

A. diffusion
B. pressure flow
C. translocation
D. active transport

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks how minerals enter a plant, providing four options: diffusion, pressure flow, translocation, and active transport.

2. **Identifying the Process**: Minerals are absorbed by plants from the soil. They are typically present in the soil as charged particles (ions).

3. **Analyzing the Options**:
- **Diffusion**: This is a passive process where substances move from an area of higher concentration to an area of lower concentration without the need for energy. However, minerals often need to move against a concentration gradient.
- **Pressure Flow**: This refers to the movement of sugars in the phloem and is not directly related to mineral uptake.
- **Translocation**: This is the movement of substances within the plant, primarily sugars, and does not pertain to the initial uptake of minerals from the soil.
- **Active Transport**: This process requires energy (ATP) to move substances against their concentration gradient, which is necessary for the uptake of minerals from the soil where their concentration is lower compared to inside the plant cells.

4. **Conclusion**: Since minerals are charged particles that cannot easily cross cell membranes and often need to be moved from a lower concentration in the soil to a higher concentration inside the plant, the correct mechanism for their entry is **active transport**.

5. **Final Answer**: Therefore, the correct answer is (d) active transport.

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