What gives rise to antibiotic resistance?

Key pointsVARIATION: A population of bacteria aren't all identical, even having all derived from a single bacterium. Rapid genetic exchange gives rise to mutations. SELECTION PRESSURE: By adding the selectively toxic antibiotic, you select for genes which are protective against the drug (consider 'the inverse selection) (specific examples such as penicillin beta lactamase enzymes)SURVIVABILITYREPRODUCABILIY = 'pass genes on' to the next generationMain causes of antibiotic resistance?How can we mitigate the effects?How can we measure the allele frequency?