BIO 182 Chapter Notes - Chapter 44.3: Chitin, Triploblasty, Dorsal Nerve Cord
Document Summary
Lophotrocozoans: lophophore animals with tentacles that filter feed, trocophore characterized by larva, annelids. Mantle structure helps with breathing and excretion. Develop similarly to annelids but adults are very different. Ecdysozoans molting protostomes: body is covered in a cuticle, nematodes most abundant phyla of all animals, arthropods most diverse phyla of all animals. Insects most diverse group: divided by whether or not they go through metamorphosis, highly specialized egg shells, exchanges gases through small pores called spiracles. Hemichordates: dorsal nerve cord, mouth on a proboscis that is connected to the digestive tract by a pharynx. Echinoderms: fivefold symmetry, skeletons made of interlocking plates, water vascular system bulk flow through fluid-filled cavities. Chordates: larva are most similar but adult forms in each sub-phyla are very diverse, three sub-phyla. Receives nutrients in the same way as sponges but the system is much more advanced.
