Three-dimensional Learning Progression The pretest and discussion in this lesson (a) help students to anticipate and begin thinking about the questions that they will answer in this lesson and (b) help you as a teacher see how your student reason about how matter and energy are transformed when animals eat, grow, move, and breathe (digestion, biosynthesis, and cellular respiration). In the Application Activity Sequence, both activity 1.1 and activity 1.2 in this lesson serve as the “Establish the Problem” phase for all the activities in the Animals unit. Key Ideas and Practices for Each Activity In Activity 1.1, the unit pretest is useful for two purposes. Your students’ responses will help you decide how much detail you want to include during the unit, particularly details about chemical structures of materials. If your students are mostly at Level 2 in the carbon learning progression, you may want to focus on the main ideas (like the tracing of matter and energy and the Three Questions) rather than chemical structures. Your students’ responses will also provide a starting point for discussions about the focus for this unit. In Activity 1.2, through the demonstration and discussion students will come to recognize that they have many different ideas about what happens when animals grow, as well as unanswered questions. We expect many students to express Level 2 or Level 3 ideas, for example, that animals grow because their cells divide, or that gas has no mass. Key carbon-transforming processes: Digestion, Biosynthesis, and Cellular Respiration Content Boundaries and Extensions