Biology CLEP Prep Practice Exam

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Are you gearing up for the Biology CLEP exam? Prepare like a pro with our Biology CLEP Prep Practice Exam!

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Why do cells need oxygen?

To produce movement
To generate heat
To provide energy
To complete complex metabolic reactions

The correct answer is: To provide energy

Cells need oxygen to provide energy through cellular respiration, in which glucose and oxygen are used to produce ATP, the main source of energy for cells. Options A and B are incorrect because cells do not produce movement or generate heat through the use of oxygen. Option D is incorrect because while oxygen is used in a variety of metabolic reactions, it is not required to "complete" them.