Internet Activity

Bacteria

Bacterial Growth Worksheet

  1. The population of bacteria in the first frame is 2. To find out how long it takes for the population to reach 4, add one minute at a time to the Intermediate Frame until you clearly see a population of four separate bacterial cells. Click 2 or 3 minutes beyond this frame to make sure the cells do not change further. How many frames (or minutes) did it take for the population to increase from 2 to 4?


  2. Assume that the population took 20 minutes to double (from 2 to 4). How large would the bacteria population be after one hour?




  3. How large would the population be after two hours? After three hours? (Again, assume the population doubles every 20 minutes.)



  4. Graph the bacterial populations you have calculated (at 1 minute, 20 minutes, one hour, two hours, and three hours). Use the x-axis for time and the y-axis for the number of cells. Click here for graph paper.


  5. What factors limit bacterial growth?


Return to the activity page.