Certified Dietary Manager (CDM) Practice Exam

Which of the following best describes a parasite?

1. A microorganism that can cause food spoilage

2. A chemical compound used in food preservation

3. A small organism that lives within another living organism

4. A type of food pathogen that does not require a host

The correct answer is: A small organism that lives within another living organism

The correct answer describes a parasite accurately as a small organism that lives within another living organism, relying on that host for sustenance and survival. Parasites can include various microorganisms such as protozoa, helminths, and some forms of bacteria that invade their host to obtain nutrients. This relationship is often detrimental to the host, leading to disease and health issues. Other options do not represent a parasite correctly. For instance, microorganisms that cause food spoilage do so as an effect of their growth and reproduction but do not establish the same kind of intimate and dependent relationship with a host organism characteristic of parasites. Similarly, chemical compounds used in food preservation act as agents to inhibit the growth of microorganisms, rather than being living organisms that require a host. Lastly, stating that a pathogen does not require a host contradicts the definition of a parasite, which by definition relies on a host for survival. Thus, option C provides the most accurate and relevant description of a parasite in this context.