Which of the following potential pathogens are killed by antibiotics?

The correct answer is bacteria because antibiotics are specifically designed to target bacterial cells and inhibit their growth or kill them outright. Antibiotics can act by disrupting essential processes within bacterial cells, such as cell wall synthesis, protein synthesis, nucleic acid synthesis, or metabolic pathways unique to bacteria. This selective action allows antibiotics to effectively treat bacterial infections while sparing human cells.

In contrast, viruses are not affected by antibiotics because they do not possess the cellular machinery that antibiotics target; instead, they rely on host cells to replicate. Fungi, which are eukaryotic organisms, require antifungal agents for treatment as they have cell structures and biological processes that resemble those of human cells. Protozoa, which are also eukaryotic organisms, are treated with antiparasitic medications rather than antibiotics. Thus, the specificity of antibiotics for bacteria distinguishes them in the realm of antimicrobial agents.