Pupils could be reminded of their earlier work in science about living things. Ask: "How do we know if something is alive?" Gather pupils' responses and establish that all living things grow, produce young and need to feed. Ask: "What is the main difference between animals and plants?" Establish that plants do not move from place to place, as animals do. Watch the clip together. Then invite pupils to work in pairs to write a commentary that could go along with the clip. Give pupils opportunities to replay the clip and read out their commentaries to the class.