Which term describes harmful substances produced by some microorganisms?

• A. Pus
• B. Cilia
• C. Toxins
• D. Active stage

Answer: (C)

Toxins are harmful substances produced by some microorganisms. These poisonous compounds can damage tissues or disrupt normal bodily functions, and they may be secreted by bacteria (exotoxins) or released when bacteria die (endotoxins). In the context of esthetics and salon safety, recognizing that toxins exist helps explain why strict hygiene, proper cleaning, and avoidance of contaminated products are essential to protect clients.

Pus, by contrast, is a pus-filled collection of dead white blood cells, bacteria, and tissue debris that forms in response to infection—not a substance produced by microorganisms. Cilia are tiny hair-like structures on cells that help move fluids, not harmful agents. The term active stage isn’t used to describe substances produced by microorganisms; it typically refers to a phase in a microorganism’s life cycle, not to toxins.