A monoclonal antibody differs from a polyclonal antibody in that monoclonal antibodies .

Options

A. are labeled with chemicals that can be visualized .
B. are produced by cells from the same organism that produced the antigen.
C. are synthesized by population of identical , or "cloned", cells .
D. are synthesized only in living organisms.

Answer

To solve the question about the differences between monoclonal and polyclonal antibodies, we can analyze the characteristics of each type of antibody step by step.

### Step-by-Step Solution:

1. **Definition of Monoclonal Antibodies**:
- Monoclonal antibodies are antibodies that are made by identical immune cells (clones) that are all specific to the same antigen. They are produced from a single type of B cell that has been cloned.

2. **Definition of Polyclonal Antibodies**:
- Polyclonal antibodies are produced by different B cell lineages and are a mixture of antibodies that recognize multiple epitopes on the same antigen. They are generated in response to an antigen and can bind to different parts of that antigen.

3. **Key Differences**:
- **Source**: Monoclonal antibodies come from a single clone of B cells, while polyclonal antibodies come from multiple B cell clones.
- **Specificity**: Monoclonal antibodies are specific to one epitope of an antigen, whereas polyclonal antibodies can recognize multiple epitopes.
- **Production**: Monoclonal antibodies are produced in a laboratory setting (e.g., hybridoma technology), while polyclonal antibodies are produced naturally in response to an antigen.

4. **Correct Statement**:
- The correct statement regarding monoclonal antibodies is that they are synthesized by a population of identical or clonal cells. This is the key distinguishing feature that sets them apart from polyclonal antibodies.

5. **Conclusion**:
- Therefore, the main difference is that monoclonal antibodies are produced by a single clone of cells, making them uniform in their specificity, while polyclonal antibodies are produced by multiple clones, resulting in a diverse mixture of antibodies.