Question

Given below are two statements:
Statement (I): A deficiency of an essential nutrient makes it impossible for the plant to complete the vegetative or reproductive stages of its life cycle.
Statement (II): Such deficiency is specific to the element in question and can be prevented or corrected only by supplying this element.
In light of the above statements, choose the most appropriate answer from the options given below.

• A. Both Statement (I) and Statement (II) are correct.
• B. Both Statement (I) and Statement (II) are incorrect.
• C. Statement (I) is correct but Statement (II) is incorrect.
• D. Statement (I) is incorrect but Statement (II) is correct.

Hint:

Remember Arnon and Stout's three criteria of essentiality (1939):
1. Plant cannot complete its life cycle.
2. The deficiency is highly specific (cannot be replaced).
3. The element is directly involved in plant metabolism.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
To establish whether a chemical element is truly essential for plant growth and development, soil scientists and plant physiologists refer to the "Criteria of Essentiality" formulated by Arnon and Stout in 1939.

Step 2: Detailed Explanation:
Let us analyze both statements in the context of the Criteria of Essentiality:
Statement (I): "A deficiency of an essential nutrient makes it impossible for the plant to complete its vegetative or reproductive life cycle stages."
This is the first and primary criterion of essentiality.
An element is essential if, in its complete absence, the plant cannot form viable seeds or complete its normal vegetative growth and reproductive cycle.
Thus, Statement (I) is correct.
Statement (II): "Such deficiency is specific to the element in question and can be prevented or corrected only by supplying this element."
This is the second criterion of essentiality.
The requirement must be highly specific, meaning that the deficiency symptoms cannot be corrected or substituted by supplying any other chemically similar element (for example, Sodium cannot fully substitute Potassium).
Only the application of the specific deficient element can restore normal plant development.
Thus, Statement (II) is correct.
Both statements are classical, universally accepted rules of plant mineral nutrition.

Step 3: Final Answer:
Both Statement (I) and Statement (II) are correct.