Advanced Placement (AP) Biology 2025 – 400 Free Practice Questions to Pass the Exam

Cell communication is a critical process that allows cells to respond to their environment and communicate with one another. The stages involved in cell communication include reception, transduction, and response.

During reception, cells detect signaling molecules (ligands), which can be hormones or neurotransmitters, and these bind to specific receptors on the cell surface or inside the cell. This binding initiates a series of events that lead to the next stage.

Transduction refers to the process where the signal is converted into a form that can bring about a cellular response. This often involves a cascade of molecular interactions, typically mediated by proteins and secondary messengers, that amplify the signal within the cell.

The final stage, response, is where the cell takes action as a result of the signal. This could involve changes in gene expression, alterations in cellular metabolism, or adjustments in cell behavior.

In contrast, replication refers to the process of copying DNA to prepare for cell division, which is not related to the signaling processes of cell communication. Therefore, it does not fit within the stages of cell communication.