Genetic variation in bacteria

• Antibiotic resistance is solely due to chance, not a development of tolerance
• Penicillium is the fungus, penicillin is a chemical
• A chance mutation produces an allele that codes for an enzyme that hydrolyses penicillin
• In the presence of penicillin, an increased antibiotic resistance increases the chances of a bacterium surviving and reproducing
• Bacteria reproduces via binary fission and passes on all of its genetic information, including the mutated allele
• The allele increases in frequency in the population as the new population are more likely to survive
• Antibiotic resistance causes a directional selection