7. Prokaryotic Cell Structures & Functions

Calculate the number of cells that have grown after 12 hours starting from 100 cells that have a generation time of 1 hour.

A microbiologist is having a population of 300 E. coli bacteria in an experiment in her lab. E. coli's generation time is 15 minutes. The scientist lets the E. coli population grow for 1 hour and 45 minutes. How many E. coli bacteria are present after this time?

A microbiologist is studying the growth of Bacteria X. He allowed the population of Bacteria X to grow for 4 hours and 30 minutes, which resulted in 140,800 bacterial cells. The microbiologist realizes that he forgot to determine the size of his starting bacterial population. He knows that Bacteria X's generation time is 30 minutes, how many bacteria were in the starting population?

A pastry chef accidentally inoculated a cream pie with six S. aureus cells. If S. aureus has a generation time of 60 minutes, how many cells would be in the cream pie after 7 hours?

Which of the lines best depicts the log phase of a thermophile incubated at room temperature?

Which of the lines best depicts the log phase of Listeria monocytogenes growing in a human?

Assume you inoculated 100 facultatively anaerobic cells onto nutrient agar and incubated the plate aerobically. You then inoculated 100 cells of the same species onto nutrient agar and incubated the second plate anaerobically. After incubation for 24 hours, you should have

a. more colonies on the aerobic plate.

b. more colonies on the anaerobic plate.

c. the same number of colonies on both plates.

A bacterial culture was in log phase in the following figure. At time x, an antibacterial compound was added to the culture. Draw the lines indicating the addition of a bactericidal compound and a bacteriostatic compound. Explain why the viable count does not immediately drop to zero at x.