Biology 102 Chapter 17 - Animal Life: Invertebrates
What is an animal?
Domain: Eukarya Animal Diversity
Kingdom: Animalia
● Ingest food
● Mostly mobile
● No cell wall
● Diploid
Over a Million species described
Body Symmetry
No symmetry: Sponges Bilateral symmetry: Flatworms, Mollusks, Annelids,,
Radial symmetry: Cnidarians Nematodes, Arthropods, Echinoderms, Chordates
Sponges Cnidarians
● Sedentary Jellyfish, Anemones, Corals
● Aquatic ● Sedentary or mobile
● Filter feeders: water passes through their ● Predatory
bodies and they filter out the food ● Cnidocytes: stinging cells unique
particles. to cnidarians
Very simple body plan compared to other animals ● Medusa or polyp form
Early Development of Bilateral Animals
"Mouth First": Flatworms,
Mollusks, Annelids, Nematodes,
Arthropods
"Mouth Second": Echinoderms,
Chordates
Growth my molting: Nematodes,
Arthropods.
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What is an animal?
Domain: Eukarya Animal Diversity
Kingdom: Animalia
● Ingest food
● Mostly mobile
● No cell wall
● Diploid
Over a Million species described
Body Symmetry
No symmetry: Sponges Bilateral symmetry: Flatworms, Mollusks, Annelids,,
Radial symmetry: Cnidarians Nematodes, Arthropods, Echinoderms, Chordates
Sponges Cnidarians
● Sedentary Jellyfish, Anemones, Corals
● Aquatic ● Sedentary or mobile
● Filter feeders: water passes through their ● Predatory
bodies and they filter out the food ● Cnidocytes: stinging cells unique
particles. to cnidarians
Very simple body plan compared to other animals ● Medusa or polyp form
Early Development of Bilateral Animals
"Mouth First": Flatworms,
Mollusks, Annelids, Nematodes,
Arthropods
"Mouth Second": Echinoderms,
Chordates
Growth my molting: Nematodes,
Arthropods.
1
