Ch. 11 Animal Diversity

Term Definition
vertebrate an animal with a backbone ie: fish, human and lizard
invertebrate an animal that does not have a backbone
ie: worms, spiders, snails, crayfish, insects
radial symmetry can be divided into two parts that are nearly mirror images of each other anywhere through its CENTRAL axis ie: sea star, sea anemones
bilateral symmetry can be divided into TWO parts that are nearly mirror images of each other ie: birds, mammals
asymmetry CANNOT be divided into any two parts that are nearly mirrow images of each other ie: sponge
porifera ~ salt and freshwater filter feeders
~ oldest and most primitive of all animals and most body parts
~ appeared about 600 mya from animal-like protists
porifera example : sponges
cnidarians ~ have a hollow central cavity with one opening to body
~ all having stinging cells on their tentacles
~ different coral species form coral reefs
~ stinging cells are called nematocysts
cnidarians examples: coral, sea anemones, hydra, jelly fish
nematocysts stinging cells in cnidarians
platyhelminthes ~ only one opening (mouth)
~ also known as flat worms
platyhelminthes examples: flukes (parasites)
planarians (common freshwater worm)
tapeworm (parasites)
nematoda ~also known as round worms
~ first organism to have evolved two body openings (mouth/anus)
~ most are parasites
nematoda examples: horsehair worms, hookworms, ascaris
annelids ~ segmented worms
~ tube-like body divided into many segments
~ some are parasites
annelids examples: marine worms, earthworms, leeches
mullusks ~ bivalves ( two part hinged shell )
~ tentacled
~ cephalopod
mullusks Examples: snails and slugs
~ bivalves: clams, oysters, mussels
~ tentacled: octopi and squid
cephalopod head footed
arthropod ~ exoskeleton
~ segmented bodies
~ jointed appendages
arthropod group crustaceans: shed exoskeleton or "molt" as they grow larger
example: crab, shrimp, lobster, crayfish
arthropod group arachnids: ~ 2 body parts
~ 8 legs
examples: mites, ticks, scorpions, spiders
arthropod group many legged arthropod group:
ex: centipedes: 1 pair of legs per body segment
ex: millipede: 2 pairs of legs per body segment
arthropod group insect: ~ go through metamorphosis
~ 3 body parts
~ 6 legs
examples: butterfly, dragonfly, beetles
echinoderms ~ have spiny skin
~ have a water vascular system & "tube feet" for movement
echinoderms examples: sea urchins, sand dollar, sea cucumber, star fish or sea star
4 characteristics of all chordates 1. nerve cord
2. pharyngeal pouches
3. notocard
4. postanal tail

nerve cord develeops into spinal cord
pharyngeal pouches develops into parts of throat and inner ear for humans (gill slits)
notochord develops into backbone
* except in lancelets & tunicates
postanal tail develops into a tail except in humans (genes are turned off so we only have a tail bone)
two types of chordate invertebrates lancelets & tunicates
type of chordate vertebrates fish, amphibians, reptiles, birds and mammals
what are the characteristics of fish? ~ gills for absorbing oxygen from water
~ ectothermic ( cold-blooded)
~ evolved from tunicates/lancelets (530 may)
~ 2 chambered heart
ectothermic internal body temperature is the same as the external environment
what are the characteristics of amphibians? ~ breathe using: gills (when young), lungs, skin
~ moist, smooth skin
~ soft, gelatin eggs laid in water
~ ectothermic (cold-blooded)
~ evolved from fish (530 mya)
~ 3 chambered heart

what are the characteristics of reptiles? ~ scaly skin to reduce water loss
~ lungs (only) for breathing
~ lay soft leathery shelled eggs on land
~ ectothermic (cold-blooded)
~ evolved from amphibians (350 mya)
~ 3 or 4 chambered heart
what are characteristics of birds? ~ adaptations for flight (most species)
~ bill/beak modified for diet
~ lay hard shelled eggs
~ feathers made of keratin
~ endothermic (warm-blooded)
~ evolved from reptiles/dinosaurs (150 (mya)
~ 4 chambered heart
endothermic warm blooded
what are characteristics of mammals? ~ hair or fur
~ feed young with milk (mammary glands)
~ endothermic (warm-blooded)
~ evolved from reptiles (220 mya)
~ 4 chambered heart
fish examples: whale shark, great white shark, sun fish, walleye
birds examples: robin, wood pecker, owl, falcon
mammal examples: coyote, manatee, human
amphibian examples: frog, toad, salamander
reptile example: turtle, lizard, snake

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