Monovalents (e.g., `Na^(2),K^(+)`)_____membrane permeability while divalents (e.g., `Ca^(2+)`)_____the same.

Options

A. increase, decrease
B. decrease, increase
C. increase, increase
D. decrease, decrease

Answer

To answer the question, we need to analyze the effects of monovalent and divalent ions on membrane permeability.

### Step-by-Step Solution:

1. **Understanding Ion Types**:
- Monovalent ions are ions with a single positive charge, such as sodium (Na⁺) and potassium (K⁺).
- Divalent ions have a double positive charge, such as calcium (Ca²⁺).

2. **Size Comparison**:
- Monovalent ions (Na⁺, K⁺) are generally larger in size compared to divalent ions (Ca²⁺). This size difference plays a crucial role in their interaction with the cell membrane.

3. **Effect on Membrane Permeability**:
- Larger ions (monovalent) tend to decrease membrane permeability. This is because their larger size makes it more difficult for them to pass through the cell membrane.
- Smaller ions (divalent) can increase membrane permeability. Their smaller size allows them to pass through the membrane more easily.

4. **Conclusion**:
- Therefore, we can conclude that monovalent ions decrease membrane permeability while divalent ions increase it.

### Final Answer:
Monovalents (e.g., Na⁺, K⁺) **decrease** membrane permeability while divalents (e.g., Ca²⁺) **increase** the same.