Which of the following statements is incorrect regarding the importance of coordination compounds in biological systems ?

Options

A. Vitamin `B_(12)` used to prevent anaemia is a complex compound of zinc .
B. Haemoglobin is the red pigment of blood and contains iron .
C. Chlorophyll is the green pigments of plants and contains magnesium .
D. All are correct .

Explanation

To solve the question regarding the incorrect statement about the importance of coordination compounds in biological systems, we can follow these steps:

### Step 1: Understand the Role of Coordination Compounds
Coordination compounds play significant roles in biological systems. They are often involved in essential processes such as oxygen transport, photosynthesis, and various biochemical reactions.

### Step 2: Identify Key Coordination Compounds
1. **Vitamin B12**: This is a coordination compound that contains cobalt as its central metal ion and is crucial for preventing anemia.
2. **Hemoglobin**: This is another important coordination compound that contains iron and is responsible for transporting oxygen in the blood.
3. **Chlorophyll**: This compound contains magnesium and is essential for photosynthesis in plants.

### Step 3: Analyze the Given Statements
Now, let’s analyze the options provided in the question to find the incorrect statement:
- **Option A**: "Vitamin B12 used to prevent anemia is a complex compound of zinc."
- **Option B**: "Hemoglobin is the red pigment of blood and contains iron."
- **Option C**: "Chlorophyll is the green pigment of plants and contains magnesium."

### Step 4: Determine the Incorrect Statement
- **Option A** is incorrect because Vitamin B12 is a coordination compound of cobalt, not zinc.
- **Option B** is correct as hemoglobin does contain iron.
- **Option C** is also correct since chlorophyll contains magnesium.

### Conclusion
The incorrect statement regarding the importance of coordination compounds in biological systems is **Option A**.

### Final Answer
**Option A**: "Vitamin B12 used to prevent anemia is a complex compound of zinc" is the incorrect statement.

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