Given below are two statements:
Statement I: Potassium is accumulated passively by both the cytosol and vacuole when extracellular K+ concentrations are very low in which case it is taken up actively.
Statement II: Nitrogen is an important element that participates in the opening and closing of stomata.
In light of the above statements, choose the most appropriate answer from the options given below:
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Stomatal movement:
- K+ ions are actively taken up into guard cells for stomatal opening.
- K+ efflux leads to stomatal closing.
- Nitrogen is not directly involved in stomatal movement.
Step 1: Understanding the Question:
This question tests knowledge of potassium and nitrogen functions in plants. Step 2: Detailed Explanation: Statement I:
Potassium uptake at low extracellular concentrations is active (requires energy), not passive.
At high concentrations, it can be passively taken up.
The statement is partially incorrect because it says "accumulated passively" at low concentrations.
Wait, the statement says "accumulated passively by both the cytosol and vacuole when extracellular K+ concentrations are very low in which case it is taken up actively."
This is contradictory.
At low concentrations, K+ is taken up actively.
Thus, the statement is correct overall. Statement II:
Potassium (not nitrogen) is the key element involved in stomatal opening and closing.
Nitrogen is important for growth and chlorophyll, but not stomatal movement.
This statement is false.
Thus, Statement I is correct, but Statement II is false. Step 3: Final Answer:
Thus, Statement I is correct but Statement II is false, which corresponds to option (C). [0.5cm]
