All elements are remobilized except

Options

A. P
B. N
C. K
D. Ca

Answer

To solve the question "All elements are remobilized except," we will analyze the options provided and determine which element is not remobilized in plants.

### Step-by-Step Solution:

1. **Understanding Remobilization**:
- Remobilization refers to the process by which plants can relocate nutrients from older tissues to newer tissues, especially during periods of nutrient deficiency or stress.

2. **Identifying the Options**:
- The options given are:
- A) Phosphorus
- B) Nitrogen
- C) Potassium
- D) Calcium

3. **Analyzing Each Element**:
- **Phosphorus**: This element is relatively mobile in plants and can be remobilized from older leaves to younger tissues.
- **Nitrogen**: Nitrogen is also mobile and can be remobilized, especially during the senescence of leaves.
- **Potassium**: Potassium is known for its mobility in plants and can be remobilized as needed.
- **Calcium**: Calcium is primarily found in the cell walls of plants, particularly in the form of calcium pectate. It is considered to be immobile in plants and cannot be remobilized once it is incorporated into the cell structure.

4. **Conclusion**:
- Among the options provided, Calcium (Option D) is the element that is not remobilized in plants. Therefore, the correct answer is **D) Calcium**.

### Final Answer:
**D) Calcium**