Question

4. The doubling time of an infectious microbe is 20 minutes. How long will it take for the cell population to expand 1000-fold?

Answer 1

Doubling Time for a microbepopulation can be given as 2n
To expand population to 1000 fold the organism needs to undergo reproductive cycle n times
to get 1000times population 2n≥1000
If we put n= 10
Population expands upto 1024 times ,and 1024≥1000
Means,10 cycles of reproduction are required .
Each cycle is taking 20minutes

Thus 10 Cycles require 10×20= 200minutes

Total time taken to increase the Population above 1000 fold is 200 minutes or 3 Hour 20 minutes.