____________ metal is present in hemoglobin.

Answer

**Step-by-Step Solution:**

1. **Identify the Subject**: The question is about identifying a specific metal present in hemoglobin.

2. **Understand Hemoglobin**: Hemoglobin is a red pigment found in blood that is responsible for transporting oxygen from the lungs to the rest of the body.

3. **Function of Hemoglobin**: Hemoglobin binds with oxygen to form oxyhemoglobin, which is crucial for delivering oxygen to tissues.

4. **Identify the Metal**: The key component of hemoglobin that allows it to bind with oxygen is a metal.

5. **Determine the Metal**: The metal present in hemoglobin is iron, which is represented by the chemical symbol Fe.

6. **Fill in the Blank**: Therefore, the answer to the question is "iron."

**Final Answer**: Iron (Fe) is the metal present in hemoglobin.

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