A 0.1 ml sample of a log phase culture contains 10,000 bacterial cells/ml.It is added to 9.9 ml of fresh culture medium broth.Assume a generation time of 30 minutes,and no limiting nutrients.How many bacteria will be present in the entire broth culture after five hours?
A) 3.2 × 104
B) 5.0 × 105
C) 1.02 × 106
D) 6.0 × 106
E) 2.56 × 107

Question

Quizplus · Accepted Answer

First, we need to calculate the number of generations that will occur in five hours, with a generation time of 30 minutes:
5 hours = 300 minutes
300 minutes / 30 minutes per generation = 10 generations

Next, we calculate the final number of bacteria by using the formula Nt = N0 x 2^g, where Nt is the final number of bacteria, N0 is the initial number of bacteria, and g is the number of generations:

Nt = 10,000 cells/ml x 2^10 generations = 10,000 cells/ml x 1,024 = 10,240,000 cells/ml

However, this calculation assumes that all bacterial cells divide every 30 minutes, which is not realistic. In actuality, the rate of growth will decrease as the culture becomes denser and nutrients become limited. Therefore, we should consider this result as an upper limit and choose the closest option, which is answer C) 1.02 × 106 cells/ml.

A 01 Ml Sample of a Log Phase Culture Contains 10,000