How do bacteria become resistant to antibiotics?

That’s a really good question. Well are you familiar with the concept of Natural Selection? (assume correct explanation from the student). Yes, you’re right. It is in fact by this same mechanism that bacteria change, or a better term would be to say evolve, into becoming resistant to these antibiotics. If, lets say, an individual bacteria mutates into a form which by chance is more resistant to a particular antibiotic, for example maybe it has thicker cell walls, when the colony of bacteria is exposed to the antibiotic all the bacteria are wiped out except this single resistant individual. This individual has now no competition and will form a new colony identical to itself. In this new colony, all the millions of bacteria are now resistant to this antibiotic. This resistant strain of bacteria is now much harder to get rid of than before and can spread and infect other people. Does that answer your question?