IDENTIFYING VERTEBRATES USING A CLASSIFICATION KEY
BACKGROUND
VERTEBRATES, ANIMALS WITH BACKBONES, ARE CLASSIFIED ACCORDING TO CERTAIN CHARACTERISTICS. VERTEBRATES ARE DIVIDED INTO 5 CLASSES: FISH, AMPHIBIANS,
REPTILES, BIRDS, AND MAMMALS.
FIRST ECTOTHERMS, REFERS TO ORGANISMS THAT CONTROL BODY TEMPERATURE THROUGH EXTERNAL MEANS. ECTOTHERM IS FROM THE GREEK ECTOS, OUTSIDE AND THERME,
HEAT AS A RESULT, ORGANISMS ARE DEPENDENT ON ENVIRONMENTAL HEAT SOURCES AND HAVE RELATIVELY LOW METABOLIC RATES. A SALMON IS A FISH BECAUSE IT IS
ECTOTHERMIC, LIVES IN THE WATER, BREATHES WITH GILLS, LAYS EGGS IN WATER, AND HAS FINS AND SCALES. SNAKES, TURTLES, AND LIZARDS ARE ALL REPTILES BECAUSE
THEY ARE ECTOTHERMIC, THEY BREATH WITH LUNGS, THEY LAY EGGS ON DRY LAND, AND ARE COVERED WITH SCALES.
THE NAME "AMPHIBIAN" COMES FROM THE LATIN FOR "TWO LIVES", WHICH REFERS TO ALL AMPHIBIANS HAVING A LARVAL STAGE AND AN ADULT STAGE. THIS IS UNIQUE IN THE
VERTEBRATE WORLD, BECAUSE FISH, REPTILES, BIRDS, AND MAMMALS ARE ALL BORN AS SMALL VERSIONS OF THE ADULT, NOT A COMPLETELY DIFFERENT FORM. THIS DUAL LIFE,
ONE AQUATIC WITH GILLS AND ONE TERRESTRIAL WITH LUNGS, MAY BE REPRESENTATIVE OF THE EVOLUTION OF ANIMALS OUT OF WATER AND ONTO DRY LAND. FROGS, TOADS,
SALAMANDERS, AND NEWTS ARE ALL AMPHIBIANS BECAUSE THEY ARE ECTOTHERMS, HAVE NO SCALES, HAIR, OR FEATHERS, THEIR SKIN IS MOIST, THEY BREATH WITH LUNGS,
THEY LAY EGGS IN WATER, AND THEIR LIFE CYCLE HAS 2 STAGES, THE LARVAL STAGE AND THE ADULT STAGE.
NEXT, ENDOTHERMY IS THE ABILITY OF CREATURES TO CONTROL THEIR BODY TEMPERATURES THROUGH INTERNAL MEANS SUCH AS MUSCLE SHIVERING OR FAT BURNING.
ENDOTHERMIC IS FROM THE GREEK: ENDON, WITHIN AND THERM, HEAT. BLUE JAYS, ROBINS, AND DUCKS ARE ALL BIRDS BECAUSE THEY ARE ENDOTHERMS, HAVE FEATHERS,
WINGS, AN LAY EGGS. DEER, MICE, OPOSSUMS, RACCOONS, AND HUMANS ARE MAMMALS BECAUSE THEY ARE ENDOTHERMIC, HAVE HAIR, AND NOURISH THEIR YOUNG ON MILK.
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2
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5
6
7
8
9
10
PECTORAL FIN
PECTORAL FIN
COMPLETE THE DATA TABLE BY CHECKING (√) THE CHARACTERISTICS OF EACH SUBJECT
#
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2
3
4
5
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7
8
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DOMED
TORTOISE
DODO
BIRD
UTAH LAKE
SCULPIN
TEXAS RED
WOLF
PASSENGER
PIGEON
EASTERN
ELK
ROUND
ISLAND BOA
GREEN TREE
FROG
OREGON
BISON
RED BAND
TROUT
FINS
WINGS
APPENDAGES
FORELEGS
HINDLEGS
VERTEBRATE DATA TABLE
BODY COVERING
HORNS
MOIST SKIN
SCALES FEATHERS
HAIR
TEMPERATURE REGULATION
ENDOTHERMIC
ECTOTHERMIC
BREATHING
GILLS
LUNGS
DICHOTOMOUS KEY TO VERTEBRATES
1. IDENTIFY AND NAME THE ANIMAL SUBJECT FROM THE VERTIBRATE DATA TABLE
2. REMEMBER TO BEGIN WITH #1 FOR EACH ANIMAL SUBJECT
1.
A. IS ENDOTHERMIC
GO TO #2
B. IS ECTOTHERMIC
GO TO #6
2.
A. HAS FEATHERS
B. HAS HAIR OR FUR
GO TO #3
GO TO #4
3.
A. HAS NARROW STRAIGHT BEAK
B. HAS WIDE, CROOKED BEAK
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4.
A. HAS HORNS
B. HAS NO HORNS
GO TO #5
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5.
A. HORNS HAVE MANY BRANCHES
B. HORNS HAVE NO BRANCHES
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6.
A. BREATHS WITH GILLS
B. BREATHES WITH LUNGS
GO TO #7
GO TO #8
7.
A. HAS LARGE PECTORAL FINS
B. HAS SMALL PECTORAL FINS
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8.
A. HAS SCALY SKIN
B. HAS MOIST SKIN
GO TO #9
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9.
A. HAS FRONT AND HIND LEGS
B. HAS NO LEGS
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ANSWER QUESTIONS
1. DESCRIBE ECTOTHERM.
2. DESCRIBE ENDOTHERM.
3. HOW ARE AMPHIBIANS DIFFERENT FROM OTHER ANIMALS?
4. WHICH ANIMALS ON THE DATA TABLE ARE:
FISH =
AMPHIBIANS =
REPTILES =
BIRDS =
MAMMALS =
5. WHICH OF THE PAIRS OF VERTEBRATE CLASSES ARE MOST SIMILAR?
A. BIRDS AND FISH
B. AMPHIBIANS AND REPTILES
C. REPTILES AND MAMMALS
D. FISH AND MAMMALS
6. TO WHICH VERTEBRATE CLASS DO HUMANS BELONG? EXPLAIN.
DEVELOP A CLASSIFICATION KEY FOR THE MYTHOLOGICAL CREATURES:
SPHINX = BODY OF A LION, UPPER PART OF A WOMAN
PEGASUS = WINGED HORSE
CHIMERA = FRONT A COMBINATION OF A LION AND A GOAT, HIND A SERPENT, BREATHES FIRE
CENTAUR = MAN FROM HEAD TO WAIST, REMAINDER OF BODY A HORSE
GRIFFIN = BODY OF A LION, HEAD AND WINGS OF AN EAGLE, BACK COVERED WITH FEATHERS
UNICORN = BODY OF A HORSE, HEAD OF A DEER, FEET OF AN ELEPHANT, TAIL OF A BOAR,
SINGLE HORN ON FOREHEAD
1.
A. PART OF BODY IS HUMAN
B. NONE OF BODY IS HUMAN
GO TO #2
GO TO #3
2.
A. __________________________________
B. __________________________________
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3.
A. __________________________________
B. __________________________________
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4.
A. __________________________________
B. __________________________________
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5.
A. __________________________________
B. __________________________________
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