Common cold is not cured by antibiotics because it is

Options

A. caused by a virus
B. caused by a Gram-positive bacterium
C. caused by a GRam - negative bacterium
D. not an infectious disease.

Answer

### Step-by-Step Solution:

1. **Understanding the Common Cold**: The common cold is a respiratory illness that primarily affects the upper respiratory tract, particularly the nasal epithelium. It is characterized by symptoms such as a runny nose, coughing, and sometimes a mild fever.

2. **Identifying the Causative Agent**: The common cold is primarily caused by a virus known as rhinovirus. This is an important detail because it helps us understand why antibiotics are ineffective.

3. **Role of Antibiotics**: Antibiotics are medications that are designed to target and kill bacteria or inhibit their growth. They work by attacking specific structures in bacterial cells, such as the cell wall.

4. **Differences Between Viruses and Bacteria**: Unlike bacteria, viruses do not have a cell wall. Instead, they consist of genetic material (DNA or RNA) surrounded by a protein coat. This fundamental difference means that antibiotics, which target bacterial structures, cannot affect viruses.

5. **Conclusion**: Since the common cold is caused by a virus (rhinovirus), antibiotics are ineffective in treating it. Therefore, the correct answer to the question is that the common cold is not cured by antibiotics because it is caused by a virus.

### Final Answer:
Common cold is not cured by antibiotics because it is caused by a virus.

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