Question

Vibrio fischeri are bioluminescent and are frequently found living in the light organs of bobtail squids. The production of light is regulated via quorum sensing. The bacteria begin to enter the light organ shortly after birth of the squid. If there are 1x10⁴ bacteria present an hour after birth and a quorum of 1x10¹⁰ bacteria required for bioluminescence, how much longer will it take before light will begin to be produced? (Assume a mean growth rate constant of 0.5 generations/hour).

A. 40 hours

B. 40 minutes

C. 10 hours

D. 10 minutes

E. Impossible to determine without more information

Answer 1

The correct answer is A. 40 hours

For one generation the time taken is 2 hours.

So if the beginning population is 1X104 and for becoming 2X104 it will take 2 hours and then for becoming 4X104 it will take 4hours, for 8X104 it will take 6hours. This way if you calculate, you will end up at 40 hours.