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Ch 28.1. What is an Animal?. ?. Cnidaria: jelly fish, corals, sponges etc. Chordata: sea squirts, lizards, fishes, humans. . . . Nematoda: Roundworms. Echinodermata: starfish, sea urchins, sea cucumbers . . . Platyhelminthes: planaria, tapeworm . . .
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Ch 28.1 • What is an Animal?
Animal ?? • Yes.
All animals: • Are multicellular • Feed on other organisms • Can move in some way to obtain food • Break down food to be used as energy or building tissue. • Unlike plants, animals have no cell walls to support the body.
Obtaining food: • Heterotrophic: They obtain energy and nutrients from outside sources. • Move to find food: birds, humans . . • Draw food toward them: barnacles, sponges . .
Digest food: • Internal: intestines: frogs, fish • Intercellular: inside cells: sponges, flatworms
Development of Animals: • Sperm finds egg
Zygote • Sperm and egg are one object, one cell, ready to start multiplying.
In all animals: See figure 28.5 • Sperm and egg • Zygote • 2 cell • 4 cell • 8 cell • Blastula: ball of cells • Gastrula: infolding
Animal Body Plans: • Asymmetry: irregularly shaped • Radial symmetry: left and right are equal if cut down ANY middle • Bilateral symmetry: left and right from midline equals mirror image
Body plans for Bilateral symmetry: • All have body cavities where internal organs are found. • Accept Acoelomates: flatworms: 3 cell layers w/ digestive tract but no body cavities.
Pseudocoelomate: Roundworms: a Fluid-filled body cavity partly lined.
Coelomate: Segmented worms, fish, lizards, humans, . . . Internal organs are in the open cavety (coelom) Spinal cord skin
Protection: • Exoskeleton: hard outside • Endoskeloton: support framework inside body.
Last slide • Invertebrate: an animal w/out a backbone. • Vertebrate: with a backbone
Quiz • Tomorrow when you walk in on the information you just wrote down. • Open note, open book. • Limited time per question.