Choose the correct statement.

Options

A. (a) Solution culture (hydroponics ) contains all essential elements except one, the usefulness of which is to be determined
B. (b) In Aeroponics roots are dipped in solution culture rich in air
C. (c) Potometer is used to measure degree of opening of stomata
D. (d) All of the above

Answer

To solve the question "Choose the correct statement," we need to analyze each statement provided in the options. Here’s a step-by-step breakdown of the solution:

### Step 1: Analyze Statement A
- **Statement A**: "Solution culture or also called hydroponics contain all essential elements except one, the usefulness of which is to be determined."
- **Explanation**: Hydroponics is a method of growing plants without soil, using a nutrient solution that contains all essential minerals except one, which is still under investigation for its role. This statement is correct.

### Step 2: Analyze Statement B
- **Statement B**: "In aeroponics, roots are dipped in solution culture rich in air."
- **Explanation**: Aeroponics involves suspending the roots of plants in the air and misting them with a nutrient solution. The roots are not dipped in a solution; instead, they are exposed to air. This statement is incorrect.

### Step 3: Analyze Statement C
- **Statement C**: "Potometer is used to measure the degree of opening of stomata."
- **Explanation**: A potometer is an instrument used to measure the rate of water uptake by a plant, which is related to transpiration. It does not measure the degree of stomatal opening. This statement is also incorrect.

### Step 4: Conclusion
- After analyzing all statements, we find that only Statement A is correct. Therefore, the correct answer is **A**.

### Final Answer:
The correct statement is **A**: "Solution culture or also called hydroponics contain all essential elements except one, the usefulness of which is to be determined."

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