Biochemical Oxygen Demand (BOD) is a measure of:

Options

A. Industrial wastes poured into water bodies
B. Extent to which water is polluted with organic compounds.
C. Amount of carbon monoxide inseparably combined with haemoglobin
D. Amount of oxygen needed by green plants during night.

Answer

**Step-by-Step Solution:**

1. **Understanding BOD**: Biochemical Oxygen Demand (BOD) is defined as the amount of dissolved oxygen that aerobic organisms will consume while decomposing organic matter in water. This measurement is taken over a specific period of time and at a certain temperature.

2. **Purpose of BOD Measurement**: The primary purpose of measuring BOD is to assess the degree of pollution in water bodies. It indicates the extent to which organic matter and other waste materials are present in the water.

3. **BOD and Pollution**: A higher BOD value suggests a higher level of organic pollution, as more oxygen is required for the breakdown of organic materials. Conversely, a lower BOD indicates cleaner water with less organic contamination.

4. **Ultimate BOD**: The ultimate BOD refers to the total amount of oxygen consumed when the biological reaction is allowed to proceed to completion. This is important for understanding the full impact of organic waste on water quality.

5. **Evaluating Options**: When looking at the options provided:
- **Industrial waste poured in water bodies**: This is incorrect as it does not specifically measure BOD.
- **Amount of carbon monoxide inseparably combined with hemoglobin**: This is unrelated to BOD.
- **Amount of oxygen needed by green plants during the night**: This is also incorrect as it does not pertain to BOD.

6. **Correct Answer**: The correct interpretation of BOD is that it measures the extent to which water is polluted with organic compounds or other waste materials.

**Final Answer**: Biochemical Oxygen Demand (BOD) is a measure of the extent to which water is polluted with organic compounds.

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