1. Kingdom Animalia Lower Invertebrates

2. Characteristics: eukaryotic multicellular heterotrophic consumers no cell walls sexual and asexual reproduction locomotion 99% invertebrates

3. symmetry of body plan: asymmetry – no symmetry radial – central point; can be divided into equal sections bilateral – can be divided into 2 mirrored halves cephalization – concentration of sense organs toward anterior end (associated with development of a head)

5. anterior – region of a bilaterally symmetrical organism toward the head end posterior – region of a bilaterally symmetrical organism toward the tail end dorsal – back side of a bilaterally symmetrical organism ventral – under side of a bilaterally symmetrical organism lateral – to the side of a bilaterally symmetrical organism

6. A. Phylum Porifera sponges simplest animals invertebrates adults sessile, filter feeders (larvae are free- swimming) water vascular system – pumps large amts. of water through porous body; all aquatic asymmetrical 2 cell types: amoebocytes choanocytes – (collared cells)

8. A. Phylum Porifera osculum – opening at top of sponge; water exits atrium – open chamber composed of spicules – framework of the sponge classified by spicule composition: 1) Class Calcarea – calcium carbonate spicules 2) Class Hexactinella – siliceous spicules 3) Class Demospongia – spongin reproduce sexually by egg and sperm asexually by budding

10. B. Phylum Cnidaria corals, jellyfish, anemones radial symmetry entirely aquatic (marine, few fw) possess stinging cells (nematocysts) on tentacles nerve net – simple nervous system 3 classes: 1) Class Hydrozoa – ex: Hydra 2) Class Scyphozoa – ex: most jellyfish 3) Class Anthozoa – ex: corals, anemones

12. B. Phylum Cnidaria classified by life cycle stages: 1) medusa – free swimming 2) polyp – attached stage reproduction: asexually by budding sexually by egg & sperm

14. C. Phylum Platyhelminthes flatworms incomplete digestive system (one opening) bilateral symmetry flame cells for excretion (nephridia) 1) Class Turbellaria – free-living ex: planarian 2) Class Trematoda – parasitic ex: liver fluke 3) Class Cestoda – parasitic ex: tapeworm

16. D. Phylum Nematoda roundworms complete digestive system – 2 openings bilateral symmetry tube within a tube body plan ex: Ascaris, hookworms, filarial worms, eyeworms, Trichinella – cause trichinosis

17. E. Phylum Annelida segmented worms name means “little ring” fw, sw, terrestrial true coelom – fluid-filled body cavity complete digestive system all organ systems present closed circulatory system – blood is confined to vessels

18. E. Phylum Annelida classified by their number of setae – bristles for locomotion 3 classes: 1) Class Hirudinea – no setae ex: leeches *parasitic, fw or sw 2) Class Polychaeta – many setae ex: bristleworm *most marine 3) Class Oligochaeta – few setae ex: earthworms *terrestrial

20. Earthworm prostomium – liplike covering over mouth; pushes soil into mouth clitellum – banded structure that functions in reproduction by secreting a mucus ring which carries fertilized eggs and is left behind as a cocoon reproductive system: hermaphrodite – has both male & female sex organs ovaries – produce eggs testes – produce sperm seminal vesicles – store worm’s own sperm seminal receptacles – receive other worm’s sperm

21. Earthworm digestive system: complete (mouth & anus) mouth – takes in food pharynx – sucks in soil esophagus – transports food to crop crop – stores food gizzard – grinds food intestine – absorbs nutrients anus – releases wastes

22. Earthworm circulatory system: closed; will be black no heart; has aortic arches (pump blood) dorsal blood vessel – carries blood to aortic arches ventral blood vessel – carries blood to posterior end respiratory system: O 2 & CO 2 (gases) exchanged through moist skin; kept moist by secreting mucus

23. Earthworm excretory system: nephridia – “little kidneys” remove wastes from blood cuticle – outer skin-like covering on worm that secretes mucus nervous system: fused nerve cells (ganglia) simple brain that sends/receives messages ventral nerve cord – carries messages to/from body from/to ganglia