Which of the following is characteristic of resident normal flora?

• A. They are acquired only during illness.
• B. They are consistently present on body surfaces and mucous membranes.
• C. They are eliminated by routine handwashing.
• D. They always cause disease in healthy individuals.

Answer: (B)

Verified step by step guidance

1. Understand the definition of resident normal flora: these are microorganisms that are consistently found on or within the human body under normal conditions.
2. Recognize that resident normal flora are typically stable populations that colonize specific body sites such as the skin, mucous membranes, and gastrointestinal tract.
3. Note that resident normal flora are not usually removed by routine handwashing because they are well-adapted to their environment and often reside in deeper layers or protected areas.
4. Understand that resident normal flora do not cause disease in healthy individuals; instead, they often play beneficial roles such as preventing colonization by pathogens and aiding in immune system development.
5. Conclude that the characteristic feature of resident normal flora is their consistent presence on body surfaces and mucous membranes, distinguishing them from transient flora or pathogens.