Bone marrow occurs in

Options

A. ribs and sternum
B. ribs, sternum and cranial bones
C. ribs and cranial bones
D. only ribs

Answer

**Step-by-Step Solution:**

1. **Understanding Bone Marrow**: Bone marrow is a semi-solid tissue found within certain bones. It plays a crucial role in the production of blood cells, including red blood cells, white blood cells, and platelets.

2. **Location of Bone Marrow**: Bone marrow is primarily located in the spongy or cancellous part of bones. This is typically found in the long bones of the body.

3. **Identifying the Options**: The question provides four options regarding where bone marrow occurs:
- Option 1: Ribs and sternum
- Option 2: Ribs, sternum, and cranial bones
- Option 3: Ribs and cranial bones
- Option 4: Only ribs

4. **Analyzing Each Option**:
- **Option 1**: Ribs and sternum - This option is correct as both ribs and sternum contain bone marrow.
- **Option 2**: Ribs, sternum, and cranial bones - This option is incorrect because cranial bones do not contain bone marrow.
- **Option 3**: Ribs and cranial bones - This option is also incorrect for the same reason as option 2.
- **Option 4**: Only ribs - This option is incorrect because it excludes the sternum, which also contains bone marrow.

5. **Conclusion**: Based on the analysis, the correct answer is **Option 1: Ribs and sternum**.

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