Which part of human body is the first to be affected by nuclear radiations?

Options

A. Brain
B. Lungs
C. Liver
D. Bone marrow

Answer

**Step-by-Step Solution:**

1. **Understanding Nuclear Radiation**: Begin by recognizing that nuclear radiation is harmful and can affect various parts of the human body. It is important to know that it can damage cells and alter DNA.

2. **Identifying Affected Areas**: The question asks which part of the body is affected first. The options provided are brain, lungs, liver, and bone marrow.

3. **Analyzing the Options**:
- **Brain**: While the brain can be affected by radiation, it is not the first to be impacted.
- **Lungs**: Lungs can also suffer from radiation exposure but are not the primary target.
- **Liver**: The liver is important for detoxification but is not the first to be affected by nuclear radiation.
- **Bone Marrow**: Bone marrow is crucial for producing blood cells and contains DNA that is sensitive to radiation.

4. **Conclusion**: Nuclear radiation primarily affects the DNA within cells. Since bone marrow is responsible for producing blood cells and is rich in DNA, it is the first part of the human body to be affected by nuclear radiation.

5. **Final Answer**: Therefore, the correct answer is **D. Bone Marrow**.

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