Biological Classification - Day 2
Lesson 15 of 17
Objective: Students will be able to explain the Linnaean system use it to classify living organisms according to a variety of common features.
To start this lesson I redistribute the answered ball cladograms from the day before. Any student that proposed a different scheme than mine is called upon to explain their scheme. If no one found a different scheme, I ask, "Why do you think we all found the same classification scheme?"
Either way, I steer the conversation to the importance of classifying organisms finding similar attributes as a way to simplify their study.
I then present the One of These (snakes is not like the others) video.
At the end of the video, I pause on the last frame, and invite students to pay attention to the image. I ask, "Which of the snakes is not like the others? What does the name tell you?"
Note to teachers: If a student asks, the main difference between the Bitis and Agkistrodon genus is that Bitis inflates and deflates their body as a threat display, while Agkistrodon have an open-mouth-strike threat display. Both also differ in the head scale patterns.
I present the same slideshow as the day before, starting at slide 8 (where we left off).
As we move through the slideshow, I explain how nested categories of organisms share characteristics, and that the different scientific names are a way to help us identify similarities and differences.
In slide 13, the students are finally given the answer to the question, "Which of these cats is not like the others." As I present slides 14 and 15, I stop to allow students to look at the information, think about the names and share with a partner what the names might tell them. I then use popsicle sticks to select students to answer the embedded questions. As students give their answers, I make it a point to have them explain to the class how the family/genus/species allows them to respond to the questions (SP7 Students are formulating arguments based on solid data). During this part of the lesson students are practicing identifying patterns to determine cause and effect relationships (CCC Patterns).
Before the lesson I bookmarked and shared the three websites the students will be using on Edmodo:
As students work through the sites, they continue to recognize how patterns help scientists organize different species (CCC Patterns), as well as deriving meaning from scientific text (SP8).
In the following video I provide a walk-though of the different sites and give some tips on how to use them in class.
The student work (SW1, SW2, SW3, SW4) reveals the class was able to grasp the content. Students successfully used the guided notes and were able to determine the similarities and differences between the organisms presented in the examples. In the following video, a couple of students explain their answers. I also asked them to talk about which site they found most helpful. It is interesting to note that some prefer the content heavy site, while others prefer to practice what they learned.
To close this lesson, I pose the following question on Edmodo.
Explain which of these organisms you would expect to share the most characteristics
- Aubrieta gracilis
- Chameleo gracilis
- Mammillaria gracilis
- Aubrieta deltoidea
At this point, students should recognize that Aubrietas share more characteristics, even if gracilis appears in three species names. These are some examples of their answers.