Final answer:
The statement is true. Antibiotics are designed to work inside the body with selective toxicity, targeting bacterial structures and functions not found in human cells to treat infections while minimizing harm to the host.
Step-by-step explanation:
The statement that antibiotics usually work inside our bodies, and therefore should exhibit selective toxicity, is true. Antibiotics are designed to target specific aspects of bacterial cells, such as cell wall synthesis, protein synthesis, nucleic acid synthesis, and metabolic pathways, that are different from those of human cells, which helps to minimize harm to the host while effectively treating the infection. For instance, cell wall synthesis inhibitors like the B-lactams and glycopeptides are effective because humans do not have cell walls, making these targets unique to bacteria.
The characteristic of selective toxicity is crucial because antibiotics need to be able to discriminate between harmful bacteria and the body's own cells to reduce the risk of damaging the host's tissues and native microbiota. This selective action also helps to maintain the balance of beneficial bacteria in the body, which are important for health. However, it is worth noting that despite antibiotics' selective toxicity, they can sometimes affect beneficial bacteria, leading to issues like superinfections and the development of antibiotic resistance due to misuse and overuse of these drugs.