Carbon monoxide has greater affinity for haemoglobin as compared to oxygen :

Options

A. 2 times
B. 20 times
C. 250 times
D. 1000 times

Answer

### Step-by-Step Solution:

1. **Understanding Affinity**: The question states that carbon monoxide (CO) has a greater affinity for hemoglobin compared to oxygen (O2). Affinity in this context refers to the attraction or binding strength between a molecule and hemoglobin.

2. **Role of Hemoglobin**: Hemoglobin is a protein in red blood cells that carries oxygen from the lungs to the rest of the body. It can also bind to other gases, including carbon monoxide.

3. **Comparative Affinity**: Research shows that carbon monoxide binds to hemoglobin with a much higher affinity than oxygen. Specifically, carbon monoxide can bind to hemoglobin approximately 200 to 250 times more strongly than oxygen.

4. **Implications of High Affinity**: When carbon monoxide is present in the bloodstream, it competes with oxygen for binding sites on hemoglobin. Because of its higher affinity, carbon monoxide can effectively displace oxygen, leading to reduced oxygen transport in the body.

5. **Consequences of Carbon Monoxide Binding**: The binding of carbon monoxide to hemoglobin can result in a condition known as carbon monoxide poisoning. This occurs because the body is deprived of oxygen, leading to symptoms of suffocation and potentially fatal consequences.

6. **Conclusion**: Therefore, the statement that carbon monoxide has a greater affinity for hemoglobin than oxygen is true, and it has significant physiological implications, particularly in terms of oxygen transport and the potential for toxicity.