TAXONOMIC TWISTERS
Written By: Mary K. Bechold
Freehold Boro High School, Freehold, NJ

Standards

National Science Standards:

NJ State Science Standards: 5.1, 5.2, 5.4, 5.6, 5.7

Science Process Skills:
Communicating, presenting, observing, comparing, organizing, inferring, constructing, debating

Key Concept: Student Learning Objective

Taxonomy is the organization of living things into groups based on similar characteristics. The taxonomy system we use today has imperfections, however with more research scientists hope to gain more understanding on how best to separate living things into proper groupings.

Teaching Taxonomic Twisters:

Planning Ahead –
Background
Web Resources
Vocabulary
Materials
Print Student Worksheets

Into: Introduce the activity

Through: Main Lesson

Beyond: Extensions

Background

The marine world is mysterious. We know more about the surface of the moon than what is found in our oceans here on Earth. It is estimated that only about 20% of the ocean floor has been mapped out and explored. Marine Scientists are continually finding new species of marine invertebrates; these findings are forcing scientists to reevaluate how animals are classified.

Taxonomy is a branch of biology concerned with naming and classifying the diverse forms of life. The earliest accounts of classifying traces back to Aristotle who classified living things into plants and animals. With the increase of exploration to new lands and communications between different parts of the world scientists began to realize the classification system they had been using was ineffective. A new system had to be created if scientists were to keep abreast of all the new discoveries.

Carolus Linnaeus, the Father of Taxonomy, was a botanist and naturalist from Sweden. In the 1700s Linnaeus founded the system of classifying known as taxonomy. Linnaeus grouped organisms into large groups and broke them down several times into smaller and smaller groups based on shared characteristics. Linnaeus is also accredited with devising a two-part naming system of all living organisms, this system is known as Binomial Nomenclature, and is made up of an organism’s genus and species. While Linnaeus based his classification on organism’s shared characteristics, scientists today base their placement of organisms on a number of factors besides characteristics, such as evolutionary relationships, and DNA analysis. These differences account for the many changes that have been made to Linnaeus’s original system. Although changes have been made the original framework is still in existence and has aided scientists with their work for many years.

Scientists use classification as a tool to aid them when researching organisms. Classification can be used to show how organisms are related, and used as a tool to describe evolutionary changes. The use of Binomial Nomenclature is especially important because when scientists are discussing a certain organism there is never confusion as to what organism is being discussed. The reason for this is the scientific name of an organism is always in Latin; therefore scientists from other countries, who may have different names for the same organism, can communicate effectively. There are seven taxonomic groups that make up the classification system. The largest group is called a Kingdom, and the smallest group is a species. A pictorial of the classification system is described below:

Students will be learning about taxonomy using marine animals. There are several phylums and classes that should be included in this lesson (see list below). All organisms will belong to the Kingdom Animalia. Please note that descriptions for each group can be found in any Biology or Marine Science Textbook. Also please look for the list of “helpful websites” to aid you if you are unfamiliar with a group.

Groups that should be included in Through the Activity:
Phylum-Porifera
Phylum-Cnidarian
Phylum-Echinodermata
Phylum-Molluska Class-Bi-Valve
Phylum-Molluska Class-Cephalopod
Phylum-Arthropod Class-Crustacean
Phylum-Chordata Class-Chondrichthyes
Phylum-Chordata Class-Osteichthyes
Phylum-Chordata Class-Reptilia (sea turtles)
Phylum-Chordata Class-Mammalia (*whales, seals, dolphin)
*You may wish to assign each marine mammal to different groups to show the differences found in the same class. Students usually find the differences easier to see in groups they are already familiar with.

Web Resources

General taxonomy of most organisms: http://animaldiversity.ummz.umich.edu/
Fish: www.fishnet.com
Crustaceans: www.austmus.gov.au/invertebrates/cru/

Vocabulary:

(To be discussed through out the entire lesson)
Classifying, traits, Carolus Linnaeus, sexual reproduction, asexual reproduction, external fertilization, compound eyes, simple eyes, warm-blooded, cold-blooded, endoskeleton, exoskeleton, gills, lungs

Materials:

Into the Activity
-garbage bag with various clothes
-6 bags with miscellaneous items
(all bags should have same items)

Through the Activity
-10 small paper bags with names of phylums/classes written on paper inside
-Copies of 2 sided worksheet “Taxonomic Twisters” 1 per student
-Copies of the Rubric (before construction begins)
-Pictures or preserved specimens of all the marine phyla/classes
-Materials if students are to construct animals in classroom

Beyond the Activity
-Biology or Marine Science Textbooks

Into the Activity: (Time 1-2 class periods depending on discussion time)

Gather a variety of clothes from your home include shoes, socks, pants, tops etc. and place them in a plastic bag. When students arrive into class dump all the articles on your desk and in the center top of the board, in large letters write the word “CLOTHES”. Underneath the word draw 3 arrows pointing downward.

Discuss with students how to arrange the clothes into groups. Accept all answers and begin to break down the groups of clothes into smaller and smaller groups until there is only 1 item left for each group. (Example: There is only 1 blue shirt with buttons, there is only 1 black shoe with a buckle, etc.). (If you are unsure as to how to draw the diagram on the board see FIGURE 1 below). Discuss with students the different possibilities of breaking down the clothes. Examine the different ways this task could be accomplished, discuss if any person’s suggestion are wrong. Discuss with students if there is ever is a “wrong” answer for this activity.

Break students down into 6 groups of 4 students. Have prepared for each group a bag filled with various items. Bags can be filled with almost anything: CD’s, movies or miscellaneous objects. It is important to note that all the bags should have similar objects in them. Give each group a bag and ask them to break the objects down into groups using whatever method they want. They are to record all the decisions they have made about breaking down the objects on a piece of paper in a branching format. (Example: A bag with the following items (rock, puzzle piece, tea bag, seashell, plastic flipper, plastic fork, spoon, skate egg case) may be broken down in the following way:

Once each group has broken down their bags and recorded the necessary information, have 2 groups come to the blackboard and quickly draw what their group has done. The groups will almost always have something different. TEACHER TIP: Check all groups work and pick the two groups that are the most different to present. With each groups information on the board a discussion about classification can now take place. Again discuss which group is wrong or right. Discuss what groupings are more descriptive then others (Example: The grouping of non-living vs. living items is very good where as the grouping of black things and white things is not as descriptive.) Have students brainstorm on ways they can improve this breakdown (by changing some of the headings). Have students explain why an object can not be put into a grouping twice (Example: Why isn’t the rock (which is white) also under the category white things?) Try to set up bags that will make certain questions and problems arise. Discuss what problems scientists might encounter when trying to classify a newly discovered creature.

Through the Activity (Time: 1 day to set up, 2 days in library, 3 days to construct, 3 days to present.)

NOTE: CONSTRUCTION CAN TAKE PLACE OUTSIDE SCHOOL

Place students into 10 groups; assuming this will allow 2-3 students per group. Prior to the start of class organize 10 small paper bags or boxes. (Whatever is handy will work). Label each bag with a different characteristic the students are to investigate. The bags should read:

1. Reproduction
2. How feeding/what feeding
3. Movement
4. Vision
5. Body Covering
6. Protection from predators
7. Warm or Cold Blooded
8. Live Birth/eggs
9. Type of skeleton
10. How organism Breathes

Inside the bag, place the names of all 10 phylums or classes on a scrap of paper. These names can be found below:

Phylum-Porifera
Phylum-Cnidarian
Phylum-Echinodermata
Phylum-Molluska Class-Bi-Valve
Phylum-Molluska Class-Cephalopod
Phylum-Arthropod Class-Crustacean
Phylum-Chordata Class-Chondrichthyes
Phylum-Chordata Class-Osteichthyes
Phylum-Chordata Class-Reptilia (sea turtles)
Phylum-Chordata Class-Mammalia (*whales, seals, dolphin)

Make sure each student has a photocopy of the data sheet:

Have students from each group come pick out of the bag what phylum or class they will be investigating for and record the data on their worksheet. Example: One student from each group will come up to the bag labeled “Reproduction” and pick from the bag one of the 10 phylum or classes listed above. Once all the groups have their sheets filled out and in order explain the concept of the lesson. Explain to students that they are scientists who have just discovered new creatures on the planet Mars. They must show and present their animals to the scientific world. In front of them (on their data sheet) explains all the data they have on their animal. They must construct the animals using the specific traits they have on their sheet so they can show the world what this new animal looks like. Allot 2 class days in the library to allow enough time to gather information. Students should be filling in the third column of their data sheet: Characteristics of phylum/class. Click here for an example of a Taxonomic Twisters data sheet.

Once data sheets have been collected and checked by the teacher (ensure students are in the right direction) thE newly discovered organisms can be constructed. NOTE: Once students begin to construct their organism many questions will arise. For example, a student may ask how to show that their organism has gills (since gills are found internal to animals). This is an excellent opportunity to show pictures or preserved organisms that do have gills to see if students can figure out that organisms with gills usually have gill slits and that is how they can portray gills on their organism. Make sure all students have a copy of the Rubric to help them construct their organism. Once all organisms have been constructed students should “present their scientific findings” (show there animal) to the class. Have them present in such a way that the other students can learn the differences among the phylums. Example: A student might present and say the following “This is our discovered animal, it reproduces like a mollusk in the class bi-valve which means it lays eggs externally and sperm is deposited on the eggs”.

Beyond the Activity (Time: About 2 class periods)

Choose one of the newly discovered organisms that you feel the students can work best with. Re-explain to the class that this is a newly discovered organism that a group of scientists have just discovered and they are now to try to classify it using the current classification system we use today. Students will need textbooks and possibly some information sheets to aid them in this activity. Students will attempt to classify what Kingdom, Phylum, and Class the organism should belong to. They should write the information on a piece of paper and explain why they choose a particular phylum or class. Students may have difficulty at first but try to stress to them they need to decide which traits are more important to look at. (Example: To decide the Phylum of the animal is it more important to notice that the animal has a backbone or that the organism has stinging cells?) Students may become frustrated, however this will only help you to explain how difficult it can be for scientists to organize living things. Collect students’ work and choose the best two groups for a debating match. Have each side debate over the correct placement of this new creature and explain their reasons for feeling this way. When each group has presented their side have the rest of the class decide which group is “right” and vote on a placement for this new creature. From this debate process the teacher should be able to discuss with the students the various points associated with taxonomy: Is there ever a “right” answer when placing organisms into taxonomic grouping? What problems do scientists encounter when they find a new organism? How does DNA play a role in placing organisms into correct taxonomic grouping? What would scientists do if they found a new creature that did not fit into the current classification groupings? These discussions can be interwoven throughout the year when discussing classification of plants, animals, fungi or any living thing. Additionally, having students attempt to classify such a difficult animal stresses to students what traits of an organism are important when classifying. Example: A squid has eyes however that is NOT an acceptable trait to classify a squid. This is an important concept that many students have trouble mastering. Furthermore, the concepts covered such as body covering, respiration etc. are topics that can be revisited throughout the year when studying other organisms, human anatomy or diversity.