Ascientist performs a controlled experiment. this means that select one: a. the experiment is repeated many times to ensure that the results are accurate. b. the experiment proceeds at a slow pace to guarantee that the scientist can carefully observe all reactions and process all experimental data. c. two versions of the experiment are conducted, one differing from the other by only a single variable. d. one experiment is performed, but the scientist controls the variables.

d. One experiment is performed, but the scientist control the variable.

Explanation:

In the controlled experiment the independent variable is changed in an orderly manner so that accurate changes can be observed on the dependent variable. Also in this a controlled group is also used for comparision with the changes in other variables.

cellular respiration oxidizes food into energy in the form of atps.

glycolysis (6 c hexose) > 2x atps are used > 6c hexose biphosphate > 2 x 3c triphosphate >

2 x 3c pyruvate (2x nadh produced from nad) and (4x atp produced)

pyruvate actively pumped mitochondrial matrix.