Bacteria which break down the dead organisms of the soil into nitrogen compounds are termed

Options

A. denitrifying bacteria
B. nitrifying and ammonifying bacteria
C. nitrogen fixing bacteria
D. parasitic bacteria.

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the type of bacteria that break down dead organisms in the soil into nitrogen compounds.

2. **Identifying Key Terms**: The key terms in the question are "bacteria," "break down," "dead organisms," and "nitrogen compounds."

3. **Analyzing the Options**:
- **A. Nitrifying bacteria**: These bacteria convert ammonia into nitrites and then into nitrates, but they do not directly break down dead organisms.
- **B. Nitrifying and ammonifying bacteria**: This option includes both types of bacteria. Ammonifying bacteria convert organic nitrogen from dead organisms into ammonia, which can then be further processed by nitrifying bacteria.
- **C. Nitrogen-fixing bacteria**: These bacteria convert atmospheric nitrogen into ammonia, but they do not break down dead organisms.
- **D. Parasitic bacteria**: These bacteria derive nutrients from living hosts and do not play a role in breaking down dead organisms.

4. **Conclusion**: The bacteria that break down dead organisms into nitrogen compounds include both ammonifying bacteria (which convert organic nitrogen into ammonia) and nitrifying bacteria (which convert ammonia into nitrites and nitrates). Therefore, the correct answer is **B. Nitrifying and ammonifying bacteria**.

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