Question

D1. To determine whether decreasing the O2 concentration inthe controlled environment decreases the SAC of BacteriaP, the scientists should compare the results of which of thefollowing 2 trials?

Answer 1

To determine if the decreasing of oxygen decreases the SAC of bacteria in the controlled environment, you have to compare two trials in which all factors are equal, except for the concentration of oxygen.

For example:

Trial 1: Temperature 10ºC; pH=7

Trial 4: Temperature 10ºC; pH=7

or

Trial 8: Temperature 15ºC; pH= 9

Trial 11: Temperature 15ºC; pH= 9

Any trial where all factors are equal but the oxygen concentration will be of use to compare and determine the effects of the oxygen concentration in the growth of bacteria P.

For the given options, the only one that shows two trials that meet this requirement is option A