Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

1. Ten thousand bacteria multiply into 1,000,000 bacteria in 6.67 hours. What is

ID: 150686 • Letter: 1

Question

1. Ten thousand bacteria multiply into 1,000,000 bacteria in 6.67 hours. What is the generation time? a. 1 doubling per hour b. 0.5 doublings per hour . 60 minutes d. 30 minutes e. 2 hours Eighty-five bacteria per ml contaminate a donut. The volume of the donut is 10mL. The generation time is 20 minutes. After 6 hours, what is the concentration of bacteria per mL? 2. a. 85 x 2 b. 85 x 2 c. 85 x 21 d. 85 x 10 x 2 e. 85 x 10 3. What is n when 10,000,000 cells multiply into 10" cells in 3 hours? a. og 10-log 10/0.301 b. 0.301/17-7 c. 0.301(3)/ 17-7 d. 10/0.301 e. 0.301 (17-7)/3 Beginning with a bacterial culture containing 10 organisms per ml and assuming a generation time of 45 minutes (0.75 hours), approximately how long would it take for there to be 10,000,000 cells in the population? 4. a. 600 minutes b. 30 hours . 60hours d. 15 hours e. 90 minutes 5. Calculate the growth rate constant of a bacteria if its generation time is 240 minutes. d. a. b. c. 2 generations per hour 0.5 doublings per hour 4 generations per hour 12 doublings per hour 0.25 generations per hour e.

Explanation / Answer

1.G = t / 3.3 log b/B.

t = time interval in hours or minutes

B = number of bacteria at the beginning of a time interval

b = number of bacteria at the end of the time interval

n = number of generations (number of times the cell population doubles during the time interval)

t= 6.67 hours =400.2 minutes.

So G= 400.2 divide by log 3.3 b/B.

=400.2 divide by log 3.3 b/B= 1000000/10000

400.2/3.3 ×2

400.2/6.6

=60 minutes.

5.growth rate constant:

Rate of increase of cells = µ x number of cells

The value of µ can be determined from the following equation:

ln Nt - ln N0 = µ(t - t0)