We'll be focusing on vascular plants, which have specialized supporting and water-conducting tissue called xylem and phloem , and typically possess roots, stems and leaves. Nonvascular plants, such as mosses, lack an internal conducting system for water and nutrients, so they depend on their immediate surroundings for moisture. Photosynthesis is the process by which plants transform energy from the sun into the energy they need to survive. Through photosynthesis, plants are able to convert water, carbon dioxide and minerals into oxygen and energy. Enabling the leaves and stems of a plant to stand up straight is an important function of cellulose.
Plants also lack the means to move on their own as well as a nervous system.
The nervous system is a group of organized cells that allow an organism to respond to sensory impulses. Vascular plants are classified as either gymnosperms or angiosperms . Softwood trees, such as conifers, are examples of gymnosperms. The seeds of angiosperms are enclosed within fruits, often called ovaries. In addition to flowering plants, hardwood trees, such as oak, maple, hickory, birch and poplar, are classified as angiosperms.