| Non-vascular plants * Phylum Bryophyta (mosses and liverworts) | * Do not have true roots, stems and leaves. -These plants have organs that appear similar to true roots, stems and leaves but they are not true organs. Because of the lack of roots and stems these plants cannot reach water under the soil and actively take it up. They absorb water directly through their cell walls and the water moves from cell to cell via osmosis. * No vascular tissue. -Vascular tissue consists of special cells for the transport of water and nutrients. The root-like, stem-like and leaf-like organs that appear on these plants are not considered true because they do not contain vascular tissue. Lack of vascular tissue limits the size of the plant because it cannot transport water and food very far against gravity. * Small size.-The characteristics described above limit the size of the plant. * Depend on water for reproduction.-This is a limitation because they cannot survive in dry areas. External water is needed for the sperm to swim to the egg. | * Mosses, * Liverworts, * Hornworts |
ANIMALIA | Vertebrates * Phyllum Chordata | * A single, hollow nerve cord runs just beneath the dorsal surface of the animal. * A flexible rod, the notochord, forms on the