Question

A loopful of bacteria containing 1000 bacterial cells is inoculated into a nutrient broth and incubated. The culture was in lag phase for 10 minutes and then went into exponential log phase growth for 5 hours. The generation time for the bacterium is 15 minutes. Which equation set up is the correct one to determine how many cells at the end of the 5 hours of log phase growth.
A. 1000 X 2^20B. 1000 X 2^4C. 1000 X 5 X 2 X 15D. 1000 X 40(Calculate numbers)

Answer 1

Answer:

The answer is A.

Explanation:

During logarithmic growth phase bacteria grows exponentially doubling every x minutes (x depends on the species). In this question doubling time/generation time is every 15 minutes and log phase takes 5 hours, which equals to the 300 minutes. During 300 minutes bacteria doubles 20 times (300/15 = 20) which equals 2^20. Bacteria culture has been started with 1000 bacterial cells so it must be added to the calculation therefore right answer is: 1000 X 2^20.