«A Lesson Plan from The Education Department The National WWII Museum 945 Magazine Street New Orleans, LA 70130 (504) 528-1944 ...»
Thanks to Penicillin… 10 © The National WWII Museum Bacteria reproduce through binary fission. One cell divides to become two cells, two cells divide to become four cells, and so forth. Infections occur when bacteria growth increases rapidly, releasing toxins and damaging healthy cells. These bacteria divide every 30 minutes. This is known as the doubling time: the time it takes for a population to double in size.
Directions: As binary fission continues, fill in the blank portions of the chart. Then answer the questions using complete sentences.
11. How long does it take for the population of bacteria to reach at least one million? 10 hours
12. Imagine that penicillin is given to treat the bacterial infection described by the chart above.
Describe how you think the population size will change over time (increase, stay the same, decrease). Be specific and use numbers in your response.
Answers will vary. Population size will decrease over time.
Critical Thinking: In his Nobel Prize acceptance speech, Alexander Fleming predicted that penicillin might become less effective at killing bacteria over time. This is called antibiotic resistance, a major problem today. How do you think bacteria become resistant to antibiotics?
Bacteria with adaptations to resist antibiotics will survive and reproduce, passing those adaptations to offspring.