Question

As per Arnon and Stout (1939) about essential nutrient, which of the following statements are correct?
A. Impossible to complete vegetative phase of life cycle.
B. Impossible to complete reproductive phase of life cycle.
C. Plant complete life cycle but less yield.
D. Plant complete life cycle with optimal yield.
E. Plant complete vegetative phase but not reproductive phase of life cycle.
Choose the correct answer from the options given below:

• A. A only
• B. A and B only
• C. A, B and E only
• D. C, D and E only

Hint:

Essential nutrient criteria (Arnon & Stout):
1. Incomplete life cycle (vegetative or reproductive).
2. Specific and cannot be replaced.
3. Direct involvement in metabolism.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Arnon and Stout (1939) proposed criteria for essentiality of nutrients.

Step 2: Detailed Explanation:
According to Arnon and Stout, a nutrient is essential if:
1. The plant cannot complete its life cycle without it (vegetative or reproductive).
2. The nutrient is specific and cannot be replaced by another.
3. The nutrient is directly involved in plant metabolism.
The criteria imply that:
- Without an essential nutrient, the plant cannot complete the vegetative phase (A).
- Without an essential nutrient, the plant cannot complete the reproductive phase (B).
- The plant may complete the vegetative phase but not the reproductive phase (E).
- C (complete life cycle but less yield) is not a criterion for essentiality.
- D (optimal yield) is not a criterion.
Thus, A, B, and E are correct.

Step 3: Final Answer:
Thus, the correct answer is A, B and E only.
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