Active transport is observed during

Options

A. Absorption of minerals by root hairs
B. Loading of minerals in xylem
C. Loading of sucrose in sieve elements
D. All the above

Answer

**Step-by-Step Solution:**

1. **Understanding Active Transport**: Active transport is a biological process where substances move across cell membranes against their concentration gradient, meaning from an area of lower concentration to an area of higher concentration. This process requires energy, typically in the form of ATP (adenosine triphosphate).

2. **Identifying the Options**:
- **Option A**: Absorption of minerals by root hairs.
- **Option B**: Loading of minerals in xylem.
- **Option C**: Loading of sucrose in companion cells.
- **Option D**: All of the above.

3. **Analyzing Each Option**:
- **Option A**: The absorption of minerals by root hairs involves active transport as root hairs take up minerals from the soil where they are in lower concentration compared to the inside of the root cells.
- **Option B**: The loading of minerals into the xylem also involves active transport, as minerals are moved from the root cells into the xylem against their concentration gradient.
- **Option C**: The loading of sucrose into companion cells is another example of active transport, as sucrose is moved from areas of lower concentration in the leaf to higher concentration in the companion cells.

4. **Conclusion**: Since all the options (A, B, and C) involve active transport processes, the correct answer is **Option D: All of the above**.

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