Biology CLEP Prep Practice Exam

Steroids are lipids that are responsible for regulating the cell cycle. While carbohydrates, nucleic acids, and other types of hormones may play a role in cellular function, they are not specifically responsible for controlling the cell cycle. Nucleic acids are responsible for storing and transmitting genetic information, while lipids serve primarily as structural components of the cell membrane and as a source of energy. Steroids, on the other hand, act as signaling molecules that regulate the cell cycle and other crucial processes in the body. Therefore, B is the correct answer.