This is a great resource for beginning cell communication and cell signaling. This worksheet, "Three Types of Cell Signaling," allows students to take responsibility for their own learning by completing a chart on autocrine, paracrine, and endocrine signaling. They define, describe, list examples, and elaborate on one of the examples. The answer key is a great item to include in a powerpoint, or use as a format for lecture. AP Biology students love to use charts as a way to organize content and safe for exam study. This could be used as an in class activity, a homework assignment, or a note-taking format.