Select the incorrect statement from the following

Options

A. Nitrogen is a constituent of amino acids and nucleic acids
B. Nitrogen is a limiting nutrient in the soil
C. Nitrogen is an inert element
D. Nitrogen is a major constituent of shells and corals

Answer

To solve the question of selecting the incorrect statement from the given options, we will evaluate each statement one by one.

### Step-by-Step Solution:

1. **Read the Options**: The first step is to carefully read each of the options provided in the question.

2. **Evaluate Option A**:
- Statement: "Nitrogen is a constituent of amino acids and nucleic acids."
- Evaluation: This statement is correct. Amino acids, which are the building blocks of proteins, contain nitrogen. Additionally, nucleic acids (DNA and RNA) also contain nitrogenous bases.

3. **Evaluate Option B**:
- Statement: "Nitrogen is a limiting nutrient in soil."
- Evaluation: This statement is also correct. Nitrogen is often a limiting nutrient in soil because it is present in the atmosphere in an inert form (N2) and must be converted into usable forms (like nitrates) for plants.

4. **Evaluate Option C**:
- Statement: "Nitrogen is an inert element."
- Evaluation: This statement is correct as well. Nitrogen gas (N2) is indeed inert under normal conditions, meaning it does not readily react with other substances.

5. **Evaluate Option D**:
- Statement: "Nitrogen is a major constituent of shells and corals."
- Evaluation: This statement is incorrect. Shells and corals are primarily made up of calcium carbonate (CaCO3), not nitrogen. Therefore, this statement is the incorrect one.

6. **Conclusion**: Based on the evaluations, the incorrect statement is Option D: "Nitrogen is a major constituent of shells and corals."

### Final Answer:
The incorrect statement is: **"Nitrogen is a major constituent of shells and corals."**