Explain how the use of antibiotics might lead to a resistant strain of bacteria arising.

-Antibiotics kill individual bacterial cells. Random mutation of the DNA in a bacterial cell might confer antibiotic resistance to that bacterial cell. A cell with the resistance mutation is less likely to be killed by the antibiotic than the cells without the mutation. It is more likely to survive exposure to the antibiotic, and therefore to reproduce (binary fission). The number of mutant cells with the resistance gene will increase, whilst the number of cells without the resistance gene will decrease. The population of cells with bacterial resistance is known as the resistant strain.-The likelihood of a resitant strain arising is increased through the improper prescription and use of antibiotics. For example, not completing a course of antibiotics exposes a population of bacteria to lower levels of the antibiotics. A lower proportion will be killed and a higher number will be able to survive and potentially pass on a genetic mutation conferring antibiotic resistance.