AP Biology Unit 4: Cell Communication and Cell Cycle

Unit 4: Cell Communication and Cell Cycle This unit ties together how cells talk to each other, how they respond internally, and how those signals ultimately control whether a cell divides, differentiates, or dies. It's one of the most integrative units on the AP exam — expect FRQs that blend signaling with homeostasis (Unit 2), gene expression (Unit 6), and even immunity (Unit 8). 4.1 Cell Communication: An Overview Cells communicate to coordinate growth, development, metabolism, and response to the environment. Communication is ancient — yeast cells use signaling molecules called mating fact…