Which term describes bacteria that do not cause disease?

• A. Nonpathogenic bacteria
• B. Pathogenic bacteria
• C. Saprophytes
• D. Microbiology

Answer: (A)

Understanding whether a microorganism causes disease is the key idea here. Bacteria that do not cause disease are described as nonpathogenic. They’re typically harmless to humans and may even be beneficial in certain contexts, such as aiding digestion or maintaining environmental balance. The reason this term is the best fit is that it directly states the absence of disease-causing capability.

In contrast, pathogenic bacteria are the ones that cause diseases, which is why they wouldn’t be described as nonpathogenic. Saprophytes refer to organisms that feed on dead or decaying matter, a lifestyle description rather than a statement about disease potential. Microbiology is the science that studies microorganisms, not a descriptor of a particular group of bacteria.