Retranslocation of minerals from mature leaf to young leaf occurs through mostly:

Options

A. Xylem
B. Phloem
C. Parenchyma
D. Apoplast

Answer

To solve the question regarding the retranslocation of minerals from mature leaves to young leaves, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the mechanism through which minerals are retranslocated from mature leaves to young leaves in plants.

2. **Identifying the Options**: The options provided are:
- Xylem
- Phloem
- Parenchyma
- Apoplast

3. **Analyzing Xylem**:
- Xylem is primarily responsible for the transport of water and dissolved minerals from the roots to other parts of the plant.
- This transport is unidirectional (from roots to leaves/stems) and does not facilitate the movement of materials between leaves.

4. **Analyzing Phloem**:
- Phloem is responsible for the transport of organic nutrients (especially sugars) and some minerals.
- It allows for bidirectional movement, meaning it can transport substances from leaves to other parts of the plant and vice versa.
- This makes phloem suitable for retranslocating minerals from mature leaves to young leaves.

5. **Analyzing Parenchyma**:
- Parenchyma cells are involved in short-distance transport and storage within the plant.
- They do not play a significant role in the long-distance transport of minerals.

6. **Analyzing Apoplast**:
- The apoplast pathway refers to the movement of water and solutes through the cell walls and intercellular spaces, but it is not a transport tissue like xylem or phloem.
- It is more associated with water movement rather than mineral retranslocation.

7. **Conclusion**: Based on the analysis, the correct answer to the question is **Phloem**, as it is the tissue responsible for the retranslocation of minerals from mature leaves to young leaves.

### Final Answer:
The retranslocation of minerals from mature leaf to young leaf occurs mostly through **Phloem**.

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