Yellowing of leaf due to loss of chlorophyll occurs due to deficiency of mainly

Options

A. Si, Se
B. Cu, Cl
C. Ca, Cu
D. Mg, S

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the yellowing of leaves due to the loss of chlorophyll, which is a symptom of a specific condition known as chlorosis.

2. **Identifying the Cause**: Chlorosis is primarily caused by a deficiency of certain essential nutrients in plants, particularly those that are involved in the synthesis of chlorophyll.

3. **Listing Essential Nutrients**: The key nutrients that are known to contribute to chlorophyll production include:
- Nitrogen
- Magnesium
- Iron
- Manganese
- Zinc
- Sulfur
- Potassium
- Molybdenum

4. **Analyzing the Options**: The question provides multiple-choice options. We need to identify which of these elements is primarily responsible for chlorophyll production and is commonly associated with chlorosis.

5. **Eliminating Incorrect Options**:
- Silicon and selenium are not involved in chlorophyll synthesis, so any option including these would be incorrect.
- Copper and chlorine are also not directly related to chlorophyll production, thus options containing these are incorrect.
- Calcium and copper do not play a significant role in chlorophyll synthesis, so options with these are also incorrect.

6. **Identifying the Correct Option**: The remaining options include magnesium and sulfur, which are indeed essential for chlorophyll synthesis. Therefore, the correct answer is the option that includes magnesium and sulfur.

7. **Conclusion**: The answer to the question is **option D**, which includes magnesium and sulfur as the main elements responsible for the yellowing of leaves due to chlorophyll deficiency.