This lesson opens with students looking for evidence that growth is occurring in living organisms. Students will use a group of pictures of an animal at different stages of its life to find evidence of the changes that occur. These changes include body size, behaviors, food sources, habitat, and mental abilities. In part 2 of the lesson, students use the video, Our Cells, Our Selves along with a graphic organizer to determine the similarities and differences between growth and development. In the final portion of the lesson students participate in a physical game that models competition between organisms for food and demonstrates the environment's impact on growth and development.