| 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
(cold-blooded) |
| 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 |
