Why is penicillin not effective in primary atypical pneumonia?

Explanation

**Step-by-Step Solution:**

1. **Understanding Pneumonia**:
- Pneumonia is an infection that causes inflammation in the lung tissue. It can be caused by various pathogens, including bacteria, viruses, and fungi.

2. **Defining Atypical Pneumonia**:
- Atypical pneumonia is a type of pneumonia that is caused by different bacteria than the common ones typically associated with pneumonia. It often presents with milder symptoms compared to typical pneumonia.

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