Erythrocytes of adult mammals are formed in

Options

A. Spleen
B. Liver
C. Bone marrow
D. Kidney

Answer

**Step-by-Step Solution:**

1. **Understanding Erythrocytes**: Erythrocytes, also known as red blood cells (RBCs), are crucial for transporting oxygen in the body. They contain hemoglobin, which binds to oxygen.

2. **Embryonic Development**: In the early weeks of embryonic development, erythrocytes are produced in the yolk sac. This is the first site of red blood cell formation.

3. **Second Trimester Production**: During the second trimester of pregnancy, the liver becomes the primary organ for the production of red blood cells. Some erythrocytes are also produced in the spleen and lymph nodes during this time.

4. **Post-Birth Formation**: After birth, the production of erythrocytes shifts entirely to the bone marrow. This is the main site for red blood cell formation in infants and children.

5. **Bone Marrow Function**: Up to the age of 5, all bones contribute to the production of erythrocytes. However, after the age of 20, erythrocyte production is mainly limited to the bone marrow of specific bones, such as the vertebrae, sternum, ribs, and ilia.

6. **Conclusion**: Therefore, the erythrocytes of adult mammals are formed in the bone marrow.

**Final Answer**: Erythrocytes of adult mammals are formed in the **bone marrow**.

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