A Level Biology Practice Exam 2025 – All-in-One Study Guide to Excel in Your A Levels!

Cell signaling refers to an intercellular communication system whereby cells send and receive signals to coordinate their functions, activities, and responses to their environment. This intricate process is essential for various biological functions, including growth, immune response, and homeostasis. Cells utilize signaling molecules such as hormones, neurotransmitters, and cytokines to convey messages to other cells, ensuring appropriate responses based on the specific context or conditions they are experiencing.

This communication can occur through direct contact between cells or through the release of signaling substances into the extracellular space, allowing signals to travel over distances. The intricacy of cell signaling pathways ensures that even subtle changes in the environment can bring about precise changes in cell behavior. In summary, understanding cell signaling is fundamental to grasping how organisms maintain coordination between different cell types, which is critical for overall function and health.