A bacteria or virus that causes clinical disease is called what?

A bacteria or virus that causes clinical disease is called what?

• A. Pathogen
• B. Antigen
• C. Founder
• D. Strangles

Answer: (A)

The main idea here is the agent that actually causes disease. A pathogen is any bacteria, virus, or other organism capable of producing illness in a host, which is why it’s the correct term for something that causes clinical disease. An antigen, on the other hand, is a molecule that the immune system recognizes and responds to—it’s not the cause of disease by itself. The other options aren’t relevant: a founder isn’t used to describe an infectious agent, and strangles is simply the name of a disease (in horses) caused by a specific bacterium, not the general term for what causes disease.

The main idea here is the agent that actually causes disease. A pathogen is any bacteria, virus, or other organism capable of producing illness in a host, which is why it’s the correct term for something that causes clinical disease. An antigen, on the other hand, is a molecule that the immune system recognizes and responds to—it’s not the cause of disease by itself. The other options aren’t relevant: a founder isn’t used to describe an infectious agent, and strangles is simply the name of a disease (in horses) caused by a specific bacterium, not the general term for what causes disease.