Which is not a biological agent of disease ?

Options

A. Fungi
B. Mycoplasma
C. Pollen
D. Bacteria

Answer

To determine which option is not a biological agent of disease, we can analyze each option provided:

1. **Fungi**: Fungi are eukaryotic organisms that can cause diseases in humans, animals, and plants. They are considered biological agents of disease.

2. **Mycoplasma**: Mycoplasma are a genus of bacteria that lack a cell wall and can cause diseases in humans, such as respiratory infections, as well as in plants. Therefore, they are also biological agents of disease.

3. **Pollen**: Pollen consists of fine to coarse particles that are the male gametophytes of plants. While pollen can cause allergic reactions in some individuals, it does not cause diseases in the traditional sense and is not considered a biological agent of disease.

4. **Bacteria**: Bacteria are well-known infectious agents that can cause a wide range of diseases in humans, animals, and plants. Thus, they are classified as biological agents of disease.

Based on this analysis, the option that is not a biological agent of disease is **C. Pollen**.

### Step-by-Step Solution:
1. **Identify the options**: Look at the provided choices: Fungi, Mycoplasma, Pollen, and Bacteria.
2. **Evaluate each option**: Determine if each option is a biological agent of disease.
- Fungi: Yes, they cause diseases.
- Mycoplasma: Yes, they cause diseases.
- Pollen: No, it does not cause diseases.
- Bacteria: Yes, they cause diseases.
3. **Conclude the answer**: Since pollen does not cause diseases, the answer is C. Pollen.