Chemotherapy Biotherapy Certification ONS Practice Testq

Which of the following is a non-specific defense mechanism?

1. Chemical barriers

2. Immunity

3. Antigens

4. Monocytes

The correct answer is: Chemical barriers

The correct choice identifies chemical barriers as a non-specific defense mechanism. Chemical barriers refer to various substances that create an environment that is hostile to pathogens. These include enzymes, acids, and antimicrobial peptides present in various bodily secretions, such as saliva, sweat, and mucus. They serve to protect the body by preventing the entry of pathogens or destroying them upon contact. Non-specific defense mechanisms are the body’s first line of defense against infection, functioning to protect against a wide range of pathogens rather than targeting specific invaders. Unlike immunity, which involves a specific response to particular antigens or pathogens, chemical barriers do not adapt or learn; they consistently act to inhibit potential threats regardless of their nature. The other options include immunity, which is a specific defense mechanism tailored to recognize and eliminate particular pathogens. Antigens are substances that are recognized as foreign by the immune system, triggering a specific immune response. Monocytes are a type of white blood cell that plays a role in the immune system, particularly in the inflammatory response, and are involved in phagocytosis, a specific action rather than a broad defensive mechanism. Understanding these distinctions helps clarify the role of chemical barriers as essential components of the innate immune system.