Dichotomous Key to the Animal Kingdom

Dichotomous Key to the Animal Kingdom Purpose: To learn to use a dichotomous classification key. Materials: Pictures representing all the classes of the subphylum Vertebrata Pictures representing the different invertebrate phyla Pictures representing the different classes of the phylum Arthropoda Procedure: 1. You will be moving and rotating through various stations set up in the room. At each station you will find a picture of an animal in the animal kingdom. You will have a few minutes to look at the picture of the animal, observe its characteristics and determine its classification within the animal kingdom. The picture will be labeled with either the letter “A” or the letter “B.” If there is an “A” on the picture, use the key called “Dichotomous Key to the Classes of the Subphylum Vertebrata.” Determine the classification of the vertebrate and record your answer in the data table. If the picture is labeled with the letter “B”, use the key called “Dichotomous Key to the Phyla of Invertebrates.” Determine the classification of the invertebrate and record your answer in the data table. If the picture is labeled with the letter “B”, and you key the animal to the phylum Arthropoda, then use the key called “Dichotomous Key to Selected Classes of the Phylum Arthropoda” to determine what class of arthropods it belongs to. Record your answer in the data table. 2. 3. 4. 5. ---------------------------------------- Dichotomous Key to the Classes of the Subphylum Vertebrata Use this key for pictures with the letter “A” 1. a. Hair present ………………………………….. Class Mammalia b. Hair absent …………………………………… Go to 2 2. a. Feathers present ……………………………. Class Aves b. Feathers absent …………………………….. Go to 3 3. a. Jaws present ………………………………… Go to 4 b. Jaws absent …………………………………. Class Agnatha 4. a. Paired fins present …………………………. Go to 5 b. Paired fins absent ………………………….. Go to 6 5. a. Skeleton is bony ……………………………. Class Osteichthyes b. Skeleton made of cartilage ………………. Class Chondrichthyes 6. a. Skin scales present ………………………… Class Reptilia b. Skin scales absent …………………………. Class Amphibia Dichotomous Key to the Phyla of Invertebrates Use this key for pictures with the letter “B” 1. a. Body symmetry radial …………………………..….….…… Go to 2 b. Body symmetry not radial ……………………………….... Go to 3 2. a. Tentacles present; body soft ……………………….…..… Phylum Cnidaria b. Tentacles absent; body hard ……………………………... Phylum Echinodermata 3. a. Exoskeleton or shell present . …………….………………. Go to 4 b. Exoskeleton absent ………….…………….……………….. Go to 5 4. a. Jointed legs and exoskeleton present ………………….. Phylum Arthropoda b. Jointed legs absent; shell present ………………………. Phylum Mollusca 5. a. Body is segmented ………………………………….….…. Phylum Annelida b. Body is not segmented ………………………………..… Phylum Platyhelminthes NOTE: If you key out an animal to the phylum Arthropoda on the above key, the use the key below to the Classes of Arthropoda to determine what class the animal is in. ---------------------------------- Dichotomous Key to Selected Classes of the Phylum Arthropoda 1. a. Walking legs; more than 5 pairs ………………………………. Go to 2 b. Walking legs; 5 or fewer pairs ………………………………… Go to 3 2. a. 1 pair of legs per body segment ………………………………. Class Chilopoda b. 2 pairs of legs per body segment .…………………………….. Class Diplopoda 3. a. Antennae present ………………………………………………… Go to 4 b. Antennae absent …………………………………………………. Class Arachnida 4. a. 1 pair of antennae ……………………….………………………. Class Insecta b. More than one pair antennae ………….………………………. Class Crustacea ufSft enceS © ic g htCio r y p Name _______________________________ Dichotomous Key to the Animal Kingdom Student Data Pages A – Vertebrate Classes Number A–1 A-2 A-3 Common Name of Animal ufSft enceiS © cg htCio r y p Class A-4 A-5 A-6 A-7 A-8 A-9 A – 10 A – 11 A – 12 A – 13 A - 14 B – Invertebrate Phyla and Arthropod Classes Number B-1 B–2 Common Name Phylum Class B–3 B–4 B–5 B–6 B–7 B–8 B–9 B – 10 B – 11 B – 12 B - 13 ufSft enceiS © cg htCio r y p Follow-Up Questions: 1. What is a dichotomous key? _____________________________________________________________________ ____________________________________________________________________________________________ 2. Why has morphology or structural similarity been used the most in classification? ____________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ 3. What are the seven levels of classification? _________________________________________________________ ____________________________________________________________________________________________ 4. Which would be the most similar: Two animals in the same class or two animals in the same phylum? ____________________________________________________________________________________________ 5. From the key, what four characteristics can you list for the Class Osteichthyes? ________________________ ____________________________________________________________________________________________ 6. From the key, what three characteristics can you list for the arthropods? _______________________________ ____________________________________________________________________________________________ 7. What further characteristics can you list for the arthropod class Insecta? _______________________________ ____________________________________________________________________________________________ 8. Why should terms like “tall, short, large, small, red, blue” be avoided when describing the traits of an organism? ___________________________________________________________________________________ 9. In very early attempts to classify organisms, the Greek philosopher, Aristotle, identified all animals as “air dwellers, land dwellers, or water dwellers”. Under this system, all of the following organisms would have been placed in the same group: Bat, grasshopper, eagle, butterfly, flying squirrel, and sparrow. In the space below, construct a dichotomous key that can be used to identify these 6 animals. ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ ____________________________________________________________________________________________ Dichotomous Key to the Animal Kingdom Student Data Pages - Answers A – Vertebrate Classes Number A–1 A-2 A-3 A-4 A-5 A-6 A-7 A-8 A-9 A – 10 A – 11 Common Name of Animal Lemur Lamprey Manta Ray Booby Clownfish Salamander Corn snake Frog Flying fish Crane Shark Class Mammalia Agnatha Chondrichthyes Aves Osteichthyes Amphibia Reptilia Amphibia Osteichthyes Aves Chondrichthyes A – 12 A – 13 A - 14 Lizard Aardvark Hagfish Reptilia Mammalia Agnatha B – Invertebrate Phyla and Arthropod Classes Number Common Name Phylum Class B-1 B–2 Spider Bristle worm Arthropoda Annelida B–3 B–4 Jellyfish Crayfish Cnidaria Arthropoda Crustacea B–5 Millipede Arthropoda Diplopoda B–6 Sea Urchin Echinodermata B–7 Scorpion Arthropoda B–8 B–9 B – 10 B – 11 Butterfly Starfish Flatworm Centipede B – 12 Crab Arthropoda B – 13 Clam Mollusca Arthropoda Echinodermata Platyhelminthes Arthropoda Arachnida Arachnida Insecta Chilopoda Crustacea ufS )ft enceiScA © kamy B w (oghrtnCiopyr Teacher Answer Key: 1. What is a dichotomous key? A dichotomous key is a classification key that gives you two choices and leads you to the next set of characteristics. By working through all of the two-paired statements, the user arrives at the proper classification for the organism. 2. Why has morphology or structural similarity been used the most in classification? The structure of the organism is: (1) very easy to see, and (2) the structures can be preserved / fossilized so that we can identify ancient organisms. 3. What are the seven levels of classification? Kingdom, Phylum, Class, Order, Family, Genus, Species 4. Which would be the most similar: Two animals in the same class or two animals in the same phylum? Two animals in the same class. 5. From the key, what four characteristics can you list for the Class Osteichthyes? Bony skeleton, paired fins, jaws present, no feathers or hair. 6. From the key, what three characteristics can you list for the arthropods? Body symmetry is not radial, exoskeleton present, and has jointed legs. 7. What further characteristics can you list for the arthropod class Insecta? 5 or fewer pairs of walking legs. Antennae present. 1 pair of antennae. 8. Why should terms like “tall, short, large, small, red, blue” be avoided when describing the traits of an organism? The size and color are the least useful in classification. Organisms can be of different sizes and of different colors and still be the in the same species. Example: Different breeds of dogs are all in the same species, but there are great differences in size, shape and color of the different breeds. 9. ufS )ft enceiScA © kamy B w (ohgrtnCiopyr In very early attempts to classify organisms, the Greek philosopher, Aristotle, identified all animals as “air dwellers, land dwellers, or water dwellers”. Under this system, all of the following organisms would have been placed in the same group: Bat, grasshopper, eagle, butterfly, flying squirrel, and sparrow. In the space below, construct a dichotomous key that can be used to identify these 6 animals. 1. a. b. Body covered with hair ---------------------------- Go to line 2 Body not covered with hair ----------------------- Go to line 3 2. a. b. Has forelimbs modified for flying ---------------- bat Has forelimbs modified for gliding -------------- flying squirrel 3. a. b. Body is covered with feathers ------------------- Go to line 4 Body not covered by feathers ------------------- Go to line 5 4. a. b. Beak is adapted for capturing prey ------------- eagle Beak is adapted for cracking small seeds ----- sparrow 5. a. b. Wings are large for body size ------------------- butterfly Wings are folded and lie flat on body --------- grasshopper NOTE: THERE WILL BE MANY POSSIBLE ANSWERS FOR THIS.