Question

Starting with 10 bacterial cells on a TSA agar plate with a 1 hour lag phase and a 30 minute generational time, how many bacterial cells will there be on the plate after 2 hours? After 12 hours?

A) 10,240 cells
B) 20,480 cells
C) 40,960 cells
D) 81,920 cells

Answer 1

After 2 hours, there will be 81,920 cells on the plate. After 12 hours, there will be 40,960 cells on the plate.

Step-by-step explanation:

To calculate the number of bacterial cells after a given time, we need to determine the number of generations that have occurred. The generation time is 30 minutes, so after 2 hours (120 minutes), there would be 120/30 = 4 generations. Starting with 10 cells, each generation doubles the number of cells. So, after 4 generations, there would be 10 x 2 x 2 x 2 x 2 = 160 cells on the plate. After 12 hours (720 minutes), there would be 720/30 = 24 generations. The number of cells would be 10 x 2^24 = 167,772,160 cells. Therefore, the correct answer is D) 81,920 cells after 2 hours and C) 40,960 cells after 12 hours.