Learn Science » Parts of a plant >>Life cycle of a plant >> Life cycle of sunflower. Root, stem, flower, leaf! In this interactive science/environmental education lesson, your students will learn plants , that will help them to identify and remember the parts of a plant .The interactive lesson explains every stage in an interesting way. The plant life cycle starts with a seed. From the outside, seeds are protected by a tough layer, called Outer Coat. But inside every seed, there is