Most of the plants obtain nitrogen from the soil in the form of

Options

A. nitrites and molecular nitrogen
B. nitrates and ammonium salts
C. nitrites and ammonium salts
D. hyponitrites and nitrates

Answer

### Step-by-Step Solution:

1. **Understanding Nitrogen Sources for Plants**:
- Plants require nitrogen for various functions, including growth and development. Nitrogen is a crucial component of amino acids, proteins, and nucleic acids.

2. **Identifying Forms of Nitrogen in Soil**:
- Nitrogen in the soil is available in several forms, including molecular nitrogen (N2), nitrates (NO3-), nitrites (NO2-), and ammonium salts (NH4+).

3. **Evaluating the Options**:
- The options provided are:
- A) Nitrides and molecular nitrogen
- B) Nitrates and ammonium salts
- C) Nitrides and ammonium salts
- D) Hyponitrates and nitrates

4. **Analyzing the Correct Forms of Nitrogen**:
- Most plants cannot directly utilize molecular nitrogen (N2) from the atmosphere. Instead, they absorb nitrogen in the form of nitrates (NO3-) and ammonium ions (NH4+).

5. **Conclusion**:
- The correct answer is **B) Nitrates and ammonium salts**. These forms of nitrogen are readily absorbed by plants from the soil.