Nitrosomonas and Nitrobacter convert

Options

A. Carbon dioxide to carbohydrates
B. Ammonium ion into nitrate
C. Nitrate ion into nitrogen molecule
D. Nitrogen into nitrate.

Answer

**Step-by-Step Solution:**

1. **Understanding the Role of Nitrosomonas and Nitrobacter**:
- Nitrosomonas and Nitrobacter are bacteria involved in the nitrogen cycle. They play crucial roles in converting nitrogen compounds in the soil.

2. **Nitrogen Fixation**:
- The nitrogen cycle begins with nitrogen fixation, where atmospheric nitrogen (N2) is converted into ammonia (NH3) by nitrogen-fixing bacteria. This is the first step in making nitrogen available to plants.

3. **Conversion of Ammonia to Nitrite**:
- Nitrosomonas is responsible for the oxidation of ammonia (NH3) into nitrite (NO2-). This process is essential as it transforms ammonia, which can be toxic in high concentrations, into a less harmful form.

4. **Conversion of Nitrite to Nitrate**:
- Nitrobacter then takes the nitrite (NO2-) produced by Nitrosomonas and converts it into nitrate (NO3-). Nitrate is a form of nitrogen that plants can readily absorb and utilize for growth.

5. **Identifying the Correct Answer**:
- Given the options, the correct conversion that Nitrosomonas and Nitrobacter are responsible for is the conversion of ammonium ions (NH4+) into nitrate (NO3-). Thus, the answer is option 2: ammonium ion into nitrate.

6. **Elimination of Incorrect Options**:
- The other options provided do not relate to the functions of Nitrosomonas and Nitrobacter:
- Carbon dioxide to carbohydrates is a process of photosynthesis, not related to these bacteria.
- Nitrate ion to nitrogen molecule is a process called denitrification, which involves different bacteria (like Thiobacillus).
- Nitrogen to nitrate cannot occur directly; it must first be converted to ammonia.

**Final Answer**: The correct conversion by Nitrosomonas and Nitrobacter is **ammonium ion into nitrate**.

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