Cells becoming resistant to bacteria; Within a population of bacteria, NO cells are resistant to antibiotics. Over time, ALL cells are resistant to antibiotics. Outline the steps of natural selection that lead to a fully resistant population:
- Within the bacterial population, the cells obtain different types of mutations. - One type of mutation is antibiotic resistance. - Some types of mutations are harmful to the cell, some have no or little effect and others provide a survival advantage. - Most mutants do not survive. - The surviving bacterial cells reproduce by binary fission. As a result the number of mutant cells increases. - The bacterial population experiences an environmental change i.e. the population is introduced to antibiotics. - The antibiotic resistant mutants now have a survival advantage over the other mutants which do not survive. - The offspring of the antibiotic resistant mutants are also antibiotic resistant. - This offspring survive and reproduce until all the cells within the bacterial population are antibiotic resistant.
