Deficiency of which of the following does not cause chlorosis?

Options

A. Mo
B. Cu
C. Fe
D. Zn

Answer

To solve the question "Deficiency of which of the following does not cause chlorosis?" we will analyze each option provided.

### Step-by-Step Solution:

1. **Understand Chlorosis**:
- Chlorosis is a condition characterized by yellowing of leaves due to insufficient chlorophyll production. It is often caused by nutrient deficiencies.

2. **Analyze Each Option**:
- **Option 1: Molybdenum**:
- Molybdenum is an essential micronutrient for plants. Its deficiency can lead to chlorosis because it is involved in nitrogen metabolism, which is crucial for chlorophyll synthesis.
- **Option 2: Copper**:
- Copper is also an essential micronutrient but is not directly involved in chlorophyll production. Its deficiency does not typically cause chlorosis, making it a potential answer.
- **Option 3: Iron**:
- Iron is critical for chlorophyll formation. A deficiency in iron leads to chlorosis, particularly in younger leaves, as it is vital for the synthesis of chlorophyll.
- **Option 4: Zinc**:
- Zinc is another essential micronutrient that plays a role in chlorophyll synthesis. A lack of zinc can result in chlorosis, as it affects the production of chlorophyll.

3. **Conclusion**:
- After evaluating all the options, we find that the deficiency of **Copper (Option 2)** does not cause chlorosis, while the other three nutrients (Molybdenum, Iron, and Zinc) do lead to chlorosis when deficient.

### Final Answer:
**Copper (Option 2)** is the correct answer as its deficiency does not cause chlorosis.