Answer: Antibiotic resistance occurs when bacteria develop the ability to survive exposure to antibiotics that were designed to kill them or stop their growth. Antibiotic resistant bacteria are free to grow, multiply and cause infection within the host even when exposed to antibiotics.Bacteria develop resistance mechanisms by using instructions provided by their DNA. Often, resistance genes are found within plasmids, small pieces of DNA that carry genetic instructions from one germ to another. This means that some bacteria can share their DNA and make other germs become resistant.