Identify the blood cells that are unique and are the most abundant among all the blood cells.

Options

A. Thrombocytes
B. Erythrocytes
C. Granulocytes
D. Leucocytes

Explanation

**Step-by-Step Solution:**

1. **Understanding Blood Cells**: Blood is composed of different types of cells, each with specific functions. The main types of blood cells include erythrocytes (red blood cells), leukocytes (white blood cells), and thrombocytes (platelets).

2. **Identifying the Unique Blood Cell**: Among these, we need to identify which one is unique and the most abundant.

3. **Analyzing the Options**:
- **Thrombocytes**: Also known as platelets, they are involved in blood clotting but are not the most abundant.
- **Erythrocytes**: These are the red blood cells responsible for transporting oxygen throughout the body. They are indeed the most abundant type of blood cell.
- **Granulocytes**: These are a type of white blood cell involved in the immune response but are not the most abundant overall.
- **Leukocytes**: This term refers to all white blood cells collectively, which are fewer in number compared to red blood cells.

4. **Conclusion**: The erythrocytes (red blood cells) are the most abundant blood cells, constituting about 40-45% of the blood volume. They are unique because they lack a nucleus, allowing them to change shape and efficiently transport oxygen.

5. **Final Answer**: The unique and most abundant blood cells are erythrocytes (red blood cells).

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