Occupational Safety and Health Administration (OSHA) SLC Practice Exam

What is a parasite?

1. An organism that causes disease

2. An organism that lives off another organism and takes nutrients

3. An organism that helps its host

4. An organism that provides shelter to its host

The correct answer is: An organism that lives off another organism and takes nutrients

The definition of a parasite is an organism that lives off another organism, often referred to as the host, and derives nutrients at the host's expense. This relationship typically harms the host in some way. For instance, parasites may consume the host's nutrients, affect its growth, reproduction, or overall health, and may even lead to disease in severe cases. The other options relate to different biological relationships. An organism that causes disease could refer to pathogens like bacteria or viruses, which are not necessarily parasites but can affect hosts. Organisms that help their host or provide shelter typically describe symbiotic relationships, such as mutualism or commensalism, where both organisms benefit or one benefits without harming the other, rather than the exploitative relationship typical of parasitism.