variation and evolution - evidence for evolution: resistant bacteria

Question 1

under ideal conditions, how fast can bacteria reproduce? what does this mean?

Answer 1

every 30 minutes meaning they can evolve rapidly

Question 2

when are antibiotics used?

Answer 2

• kill bacteria
• widely used in medicine
• used in farming to prevent animals getting bacterial diseases

Question 3

what does it mean when bacteria are antibiotic resistant?

Answer 3

they have evolved and certain strains of bacteria are no longer killed by antibiotics

Question 4

how does antibiotic resistant happen?

Answer 4

• the bacteria (pathogens) causing disease are treated with an antibiotic but one bacteria is an antibiotic resistant bacterium. this means all bacteria is killed except the bacterium that is resistant to antibiotics
• the antibiotic resistant strain survives and reproduces without competition from other bacteria
• over time population of resistant strain rises and spreads as people are not immune and no effective treatment

Question 5

how to reduce the development of antibiotic resistant strains of bacteria?

Answer 5

• not prescribe antibiotics inappropriately. no point using them to treat a virus as they have no effect
• patients should complete course of antibiotics so make sure no bacteria survives to mutate + form resistant strains
• restrict use of antibiotics in farming

Question 6

problem with scientists trying to develop new antibiotics

Answer 6

• takes a long time
• expensive
• as new antibiotic resistant bacteria evolve all the time, it is difficult to keep up