Which is essential for selective permeability of cell membrane.

Options

A. Zn
B. Ca
C. Mo
D. S

Answer

**Step-by-Step Solution:**

1. **Understanding Selective Permeability**: Selective permeability refers to the ability of a cell membrane to allow certain substances to pass through while restricting others. This property is crucial for maintaining homeostasis within the cell.

2. **Analyzing the Options**:
- **Zinc**: While zinc is important for enzyme activation and protein synthesis, it does not play a direct role in the structure or function of the cell membrane.
- **Calcium**: Calcium is a major component of the cell wall and cell membrane. It is essential for maintaining the integrity and stability of the membrane, thus contributing to its selective permeability.
- **Molybdenum**: Molybdenum acts as a cofactor in certain enzymatic reactions, particularly in nitrogen metabolism, but it does not directly influence membrane permeability.
- **Sulfur**: Sulfur is important for protein structure and enzyme synthesis, but like zinc and molybdenum, it does not directly contribute to the selective permeability of the cell membrane.

3. **Conclusion**: Among the given options, calcium is the element that is essential for the selective permeability of the cell membrane due to its role in maintaining the structural integrity of the membrane.

**Final Answer**: Calcium is essential for selective permeability of the cell membrane.

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