Classification, part 3- What is that?

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Objective

Students will model the current naming system to better demonstrate understanding of the process of binomial nomenclature. Students will also create a dichotomous key to demonstrate their understanding of how organisms are classified.

Big Idea

Binomial Nomenclature and dichotomous keys are useful processes for naming new organisms.

Warm-Up

5 minutes

Warm-Up: Compare and contrast Aristotle's and Linnaeus’ classification systems.

Instruct students to engage in table talk for 2 minutes around this review question from the previous lesson, Classification, part 1.  This question requires students to activate prior knowledge and allows for an assessment of how much students know.  Walk around and listen to students’ comments to determine whether re-teaching is necessary.

Listen for students’ ability to identify that the two naming systems are similar in that they both created rationales for grouping organisms into categories.   If this is as much as they can identify, prompt students to dig a little deeper by asking questions like:

  • Which system is more detailed and why?
  • Why is Linnaeus’ system of classification still the basis of how we classify animals today and Aristotle’s is not?

End the warm-up by allowing each group to share one thought with the whole class.  The opportunity to share thoughts allows students to practice their language skills. 

Explain that today’s lesson will allow students to examine in greater detail why Linnaeus’s naming system is universally accepted still today.

Introduce New Material

20 minutes

Inform students of the learning targets:

  • I can create and use a dichotomous key to classify an organism.
  • I can use the current classification system to name an unknown organism.

Instruct students to consider what actions would need to be taken to identify and name organisms that have never been seen before. 

Look for students to explain that they would need to try to place in the organism in one of the six kingdoms and then name the organism. Ask students to name and describe the kingdoms.  This quick formative assessment will determine whether a review of the seven kingdoms and their characteristics is needed.  If so, take the time to conduct a quick review using the graphic organizer from Classification, part 1. Review of prior content allows for repetition, which is a great way to help students reinforce learning. 

Explain that the scenario of having to name newly discovered species of organisms is not far-fetched. Share current information about recent, un-named species of organisms that had to be classified and named. Display images and share some of the more interesting webpages for organisms with names like:

Scaptia beyonceae- Point out the binomial nomenclature naming conventions. But, also point out that this particular organism was names, in part for its large golden butt as homage to Beyonce’.

Aleiodes gaga- Point out the correct binomial naming conventions. Point out that this wasp species is named in honor of Lady Gaga. 

Gaga germanotta-  Point out the correct binomial naming convention. Share that 19 varieties of ferns are named after Lady Gaga, as well.

Check for understanding by asking students which part of each of the names reflects the genus and which part, the species. Look for students to be able to identify that the sequence matters; Genus is always first and the species name is second. Use the two organisms with “gaga” in the names to highlight this point. For the organism, Aleiodes gaga, gaga is the species.  While for the Gaga germanotta, Gaga is the species.

Guided Practice

10 minutes

Explain that students will practice their ability to classify and name organisms in a GRASPS activity.  Using a LCD projector, display and explain each part of a GRASPS performance task:

GOAL- Provide a statement of the task.

ROLE- Define the role of the students in the task.

AUDIENCE- Identify the target audience within the context of the scenario.

SITUATION- Set the context of the scenario.

PRODUCT- Clarify what the students will create and why they will create it.

STANDARD- Provide students with a clear picture of success.

Distribute copies of the Taxonomy GRASPS, “What on earth is that?”. Display the GRASPS assignment and preview each component of the GRASPS, allowing volunteer students to read each of the GRASPS components aloud to the class.

Display a GRASP example so that students will be able to see how each of the components are addressed in a completed GRASPS.  Make sure that students understand that this is an exemplar that shows what it is expected in the finished product.

Model how students will complete the Product using the first organism, photosynthetic sharks. Conduct a “think aloud” to allow students to observe your thought process in creating a name and identifying the kingdom for the shark.

Think Aloud Script Example:

What are the seven kingdoms? This will help me to decide to which kingdom each of these organisms belongs.  Now, what kingdom can I place the shark in? I know sharks are typically animals because they are heterotrophs. But, this alien shark is different. I know this because the shark description says that it is photosynthetic and its fins have chlorophyll to convert sunlight to energy. Hmmm… let me look at my kingdom graphic organizer. I think the shark might belong to the plant kingdom because it uses photosynthesis as its nutrition source. 

I know that binomial nomenclature naming requires the genus name followed by the species name. The genus is a larger grouping than species. Are there other fish that are autotrophs on this list of alien organisms? Yes. So, I need to create a genus for these autotrophic fish. I will call the genus, Photosynthetic because the name indicates that they are autotrophs, able to make their own food. Since the shark is different from the goldfish, they belong to different species. I will name the species sharkus. This organism is Photosynthetic sharkus.

Remind students to refer to their notes from both the Classification, part 1 lesson and Classification, part 2 lesson for assistance.

Independent Practice

20 minutes

Distribute poster boards and markers for students’ use. Explain that the completed task involves 4 different artifacts:

  1. Create a taxonomic scheme using only kingdom, phylum, genus, and species.
  2. Create Latin-sounding names, for each organism. Include the genus and species classification.
  3. Illustrate your interpretation of each organism's appearance.
  4. Prepare a dichotomous key for these organisms. Show a brief clip on how to develop a dichotomous key. This review of dichotomous keys from the Classification, part 2 lesson should help ensure that all students are able to complete this component of the performance tasks.

Assign students to work in groups of four to complete the tasks. Take into account the specific learning abilities of students when creating the groups and strive to create groupings where lower ability students are integrated into groups of higher ability students. The assignment has four parts so that every learner can find an opportunity to contribute in a meaningful way.

Instruct students to determine within the group who will complete which part of the assignment. Encourage students to play to their strengths when deciding who will complete which tasks.

Walk around the room to monitor the groups as they work and ensure that all students are actively engaged in the completion of the tasks. Do not expect the groups to complete this assignment in one class period. It is likely that this assignment will require at least 2 class periods to complete.

Student work 1 and student work 2 represent exemplars for this assignment. While both show accurate use of the couplets to derive classification systems, student work 1 shows a higher level of thought given toward naming and drawing the organisms, with the students creating names like Toxicitic grasspolside and Photosynthous Fleaoid. 


Close

5 minutes

Display a PMI chart (Plus, Minus, Interesting).  Distribute post-it notes and ask students to list one of the following:

Plus- Something that I liked about this assignment.

Minus- Something that I did not like about this assignment.

Interesting- Something I found interesting while working on this assignment.

Typically, students will note that they like the creative aspects of naming and drawing the organisms. They do not tend to like the process of deriving the dichotomous key and many will note that they find the descriptions of the organisms to be interesting and fun.

Consider the students'  feedback, and as appropriate adjust the task to better meet the interest of future students.