Question

the combination of sulfonamides and trimethoprim to be more effective demonstrates:synergismantagonismpotentiation onlyresistancequestion 39 (1 point)selective toxicity means:the drug targets all cells equallythe drug harms only pathogens, not the hostthe drug requires a carrierthe drug is non - specific

Explanation:

• For the first question: Synergism is when the combined effect of two substances (like sulfonamides and trimethoprim) is greater than the sum of their individual effects. Antagonism would be when one substance reduces the effect of the other. Potentiation is a type of synergism where one substance increases the effect of another, but the term “synergism” is more general and appropriate here. Resistance is about microbes becoming less affected by a drug over time, which is not relevant to the combination’s enhanced effect.
• For the second question: Selective toxicity means a drug can harm pathogens (like bacteria, viruses) while not significantly harming the host (human, animal etc.). If a drug targets all cells equally, it lacks selectivity. Requiring a carrier is about drug transport (like in facilitated diffusion for some drugs into cells) and is not related to selectivity in toxicity. A non - specific drug would act on many different cell types without discrimination, which is the opposite of selective toxicity.

Answer:

• First question: Synergism
• Second question: The drug harms only pathogens, not the host