Antibiotic resistance

• Bacteria can evolve quickly because they reproduce at a fast rate. Mutations of bacteria produce new strains and some bacteria may become resistant to certain antibiotics and cannot be destroyed by them. The evolution of bacteria is an example of natural selection.
• How do bacteria become resistant to antibiotics?

  1. Random mutations occur in the genes of individual bacterial cells
  2. Some mutations protect the bacterial cells from the effects of the antibiotics
  3. Bacteria without the mutations die when the antibiotic is present
  4. Resistant bacteria can reproduce with less competition from normal bacterial strains
• Number of bacteria after binary fission= starting number of bacteria x 2^number of divisions