A bacterium was grown in two test tubes filled with media rich in glucose. One tube was sealed to produce anaerobic conditions, and the other was not. A third uninoculated, unsealed tube was used as a control. Glucose utilization by this bacterium causes acid production, which is indicated by a lightening of the media color. If the bacterium is able to produce ATP only by aerobic respiration, we expect lightening of media in ________.
A) the sealed tube only
B) the unsealed tube only
C) the sealed and unsealed tubes only
D) the control tube only
E) all three tubes

Question

Quizplus · Accepted Answer

If the bacterium is able to produce ATP only by aerobic respiration, it requires oxygen as the final electron acceptor in the electron transport chain. Therefore, in the sealed tube without oxygen, there will be no lightening of the media. In the control tube, there is no bacterial inoculation, so glucose utilization does not occur. Therefore, only the unsealed tube will show lightening of the media due to glucose utilization by the bacterium under aerobic conditions.

A Bacterium Was Grown in Two Test Tubes Filled with Media