Dichotomous Key to the Animal Kingdom

Transcription

1 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. 2. 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. 3. 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. 4. 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. 5. 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 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

2 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 Copyright Science Stuff

3 Name Dichotomous Key to the Animal Kingdom Student Data Pages A Vertebrate Classes Copyright Science Stuff Number Common Name of Animal Class A 1 A - 2 A - 3 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 Common Name Phylum Class B - 1 B 2 B 3 B 4 B 5 B 6 B 7 B 8 B 9 B 10 B 11 B 12 B - 13 Copyright Science Stuff

4 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.

5 Dichotomous Key to the Animal Kingdom Student Data Pages - Answers A Vertebrate Classes Number Common Name of Animal Class A 1 Lemur Mammalia A - 2 Lamprey Agnatha A - 3 Manta Ray Chondrichthyes A - 4 Booby Aves A - 5 Clownfish Osteichthyes A - 6 Salamander Amphibia A - 7 Corn snake Reptilia A - 8 Frog Amphibia A - 9 Flying fish Osteichthyes A 10 Crane Aves A 11 Shark Chondrichthyes A 12 Lizard Reptilia A 13 Aardvark Mammalia A - 14 Hagfish Agnatha B Invertebrate Phyla and Arthropod Classes Number Common Name Phylum Class B - 1 Spider Arthropoda Arachnida B 2 Bristle worm Annelida B 3 Jellyfish Cnidaria B 4 Crayfish Arthropoda Crustacea B 5 Millipede Arthropoda Diplopoda B 6 Sea Urchin Echinodermata B 7 Scorpion Arthropoda Arachnida B 8 Butterfly Arthropoda Insecta B 9 Starfish Echinodermata B 10 Flatworm Platyhelminthes B 11 Centipede Arthropoda Chilopoda B 12 Crab Arthropoda Crustacea B 13 Clam Mollusca Copyright Amy Brown (aka Science Stuff)

6 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. Copyright Amy Brown (aka Science Stuff)

7 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. 1. a. Body covered with hair Go to line 2 b. Body not covered with hair Go to line 3 2. a. Has forelimbs modified for flying bat b. Has forelimbs modified for gliding flying squirrel 3. a. Body is covered with feathers Go to line 4 b. Body not covered by feathers Go to line 5 4. a. Beak is adapted for capturing prey eagle b. Beak is adapted for cracking small seeds sparrow 5. a. Wings are large for body size butterfly b. Wings are folded and lie flat on body grasshopper NOTE: THERE WILL BE MANY POSSIBLE ANSWERS FOR THIS. Copyright Amy Brown (aka Science Stuff)

8 Teacher Preparation Notes: 1. You will need to obtain a collection of photographs to use in this lab. I obtained photos from magazines such as the National Geographic, Ranger Rick, and Your Big Backyard. It is very easy to find good photos on the Internet. I have included a selection of photos with this product for your use. Use the enclosed photos, or you can use your own favorite pictures. 2. I mount the photos on a card stock paper to prevent them from being damaged. If the characteristic is hard to see in the photo (such as bony or cartilaginous skeleton), I write the needed information on the card stock paper for the student to read as he looks at the picture. Laminate the photos so that they can easily be used year after year. 3. Need to conserve paper? There are several paper-conserving options: Laminate the first two pages with the dichotomous keys. Leave one copy at each lab station for the students to use. This allows you to use them year after year and reduces the amount of photocopying. Photocopy the student answer pages each year. Students can record all questions on these pages. Photocopy only a class set of the first four pages of the document. Have students record all answers on their notebook paper. 4. The answers I listed in the above data table are for the photos I like to use. You can shorten the length of the lab by using fewer of the photos. 5. The letter identification ( A or B ) on each photo is necessary to insure that the students use the right key to classify the animal. 6. You will need to teach the meaning of some terms prior to the lab if they haven t already been taught in your class. Examples: radial symmetry, bilateral symmetry, exoskeleton, etc. 7. Arrange the photos around the room and have the students rotate around the room until they have completed each station. Created by Amy Brown Science Stuff Copyright Amy Brown (aka Science Stuff) All rights reserved by author. This document is for your classroom use only. This document may not be electronically distributed or posted to a web site.