Easy question! which of the following steps is not likely to take place during cellular respiration? a oxygen combines with carbon of simple sugar. b energy molecule transfers energy to cells. c simple sugar breaks down. d energy is used up.

You can approach this question by finding one answer that is wrong or by eliminating the answers that are correct. 

Glycolysis is the breakdown of glucose into pyruvate. If you already know that glycolysis is oxygen-independent, meaning it does not require oxygen, then you immediately know that A is incorrect, making that the correct answer.

However, you can also go about it by eliminating B, C, and D. In glycolysis, glucose is breaking down with the help of ATP bringing in energy, so that means glucose, the simple sugar, is breaking down, so C is out. ATP is bringing that energy to the mitochondria, so B is out. And the energy from ATP is being consumed, so D is out.

Control variable- changedependant variable- stays the samechanging- food itemsdependant- presences of proteins