A root concentrates minerals by

Options

A. active transport
B. facilitated diffusion
C. osmosis
D. diffusion

Answer

### Step-by-Step Text Solution:

1. **Understanding the Question**: The question asks how roots concentrate minerals from the soil. This involves understanding the mechanisms of transport that roots use to absorb minerals.

2. **Identifying Transport Mechanisms**: There are several modes of transport that can be involved in the uptake of minerals:
- **Active Transport**: This process moves substances against their concentration gradient (from low to high concentration) and requires energy (ATP).
- **Facilitated Diffusion**: This is a passive process that allows substances to cross membranes with the help of specific proteins, moving along the concentration gradient (from high to low concentration).
- **Osmosis**: This specifically refers to the movement of water across a semi-permeable membrane from an area of low solute concentration to an area of high solute concentration.
- **Diffusion**: This is the movement of molecules from an area of high concentration to an area of low concentration without the need for a membrane.

3. **Analyzing Soil and Root Hair Cell Concentrations**: In the soil, the concentration of minerals is typically lower than that within the root hair cells. This creates a concentration gradient where the root hair cells have a higher concentration of minerals compared to the surrounding soil.

4. **Determining the Mechanism Used by Roots**: Since the root hair cells need to absorb minerals from the soil where their concentration is lower, they must move these minerals against the concentration gradient. This requires energy, indicating that active transport is the mechanism used.

5. **Conclusion**: Therefore, roots concentrate minerals by **active transport**.