Which ones have round and biconcave shape

Options

A. White blood cells
B. Red blood cells
C. Columnar epithelial cells
D. Nerve cells

Answer

**Step-by-Step Solution:**

1. **Understanding Cell Shapes**: To answer the question, we need to identify the shapes of the given cell types: white blood cells, red blood cells, columnar epithelial cells, and nerve cells.

2. **Analyzing Each Option**:
- **White Blood Cells (WBCs)**: These cells have a round shape but are not biconcave. They can vary in shape depending on their type (e.g., lymphocytes, neutrophils).
- **Red Blood Cells (RBCs)**: These cells are known for their unique biconcave shape, which allows them to maximize surface area for oxygen transport. They start as round cells but lose their nucleus during maturation, resulting in a biconcave shape.
- **Columnar Epithelial Cells**: These cells are elongated and have a column-like shape, not round or biconcave.
- **Nerve Cells (Neurons)**: These cells have a long and branched structure, which is distinctly different from round or biconcave shapes.

3. **Conclusion**: Based on the analysis, the only cell type that is both round and biconcave is the red blood cells (RBCs).

4. **Final Answer**: The answer to the question is option B: Red Blood Cells.

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