Lesson 8 of 14
Objective: SWBAT construct an argument based upon a model that plants have internal and external structures that function to support survival, growth, behavior and reproduction.
Engage: Carnivorous Plants
This lesson is one that students will never forget. Venus's Fly Traps in the classroom is an amazingly engaging experience. Not only are they fun to look at, students get a chance to "play" with them a little bit, deepening their understanding of these fragile, yet seemingly aggressive plants. To engage and support their understanding, I chose this video to begin our adventure for today!
I began with writing the word Carnivorous Plants on the board for them to copy in their science notebook on the right side, where notes and facts would be written. The left side is left for future sketching. As I invited them up to the SB for the video, I asked what they thought carnivorous meant? We arrived at the answer by connecting the Spanish word for meat, "carne" and suddenly they understood!
Inquiry: What makes a plant want to eat meat? This David Attenborough BBC film is an interesting clip lasting about 3 minutes showing students how Venus Fly Traps and Pitcher Plants work.
Using video to effectively engage students about a subject that is not familiar is a great way to set them up for better critical thinking later. Seeing this video offers students another perspective and grounded them prior to working with the carnivorous plant.
After the video, we took time to address these questions. I had them written on my white board prior to the lesson so they would be ready to focus on when the film was done. As usual, the discussion was rich and connective. My students are transforming into critical thinkers who connect science to life more easily now. We also made the math connection of symmetry at this point, noting that leaves of the plant have one line of symmetry.
Why do these plants eat insects?
How does it's external parts help it survive in its environment?
What external parts of the plant allow it to get food?
Where do these plants grow?
As we finished up our discussion, I transitioned into the next part by explaining exactly what was happening next and exactly what I expected from them. I gave out explicit direction for partnering, gathering materials and appointed the person who would be responsible for triggering the trap.
Observing a Venus Fly Trap
Examining Venus Fly Traps
Materials: Venus' Fly Traps, pencil or toothpick, stopwatch or timer, magnifying glasses & science notebook.
As we began this lesson, I wrote the Driving Question on the board: What external parts of the Venus Fly Trap help it to survive and reproduce?
Students were asked to create their pages of their notebooks with the right side for factual information and the left side for sketching and observations. I proceeded to explain that I wanted them to make a math connection and wrote the word "symmetry" on the board for them to trigger their prior knowledge. To engage this thinking, I asked if they remembered their Mira lesson and if someone could explain the meaning again.
Math Connection: Line Symmetry: Before my students began this investigation, they had lessons in symmetry in both a math lesson and a recent science investigation. In this lesson, students must decide how many lines of symmetry a Venus Fly Trap exhibits and put this in their notes as they observe the plant.
Grouping: I divided the class into groups of 2 or 3. Each group was given one Venus Fly Trap and one toothpick. Each student also was given their own magnifying glass for observing.
First, I asked them to sketch the entire plant in their notebook as they see it. Then, I asked them to take their magnifying glass and look at one trap. They were told then to sketch what they see including every hair and detail of the trap. At this point, I asked them to note how many lines of symmetry the trap has. I also asked them to note any flowers, sketch those and look at them through their magnifying glass.
When they were done with this step, I appointed one student ( to save time) and instructed them to take the tooth pick and gently rubs the trigger hairs on the inside of the trap as another student hits the stopwatch. When the trap is completely closed, the timer is stopped. Everyone needs to record their observations and the time it took for that trap to shut. We only did this with one trap as I explained to them that the trap will only shut so many times before it will die. So, it is important to save the plant's energy for trapping real flies instead of toothpicks.
When all students were complete with this part, I asked them to collaborate with their group and create one rich "thick milkshake" question that would help others understand the Venus Fly Trap's external parts and their function related to survival. I discussed with each group to remind them of what rich questions vs. weak questions are and provide the following examples. This helps students understand that scientists need to think deeply and observe with purpose.
An example of a rich question: What do you notice as the Venus Fly Trap closes?
An example of a weak question: How many "spikey things" does the plant have?
Once the questions were formulated, I had them type them on one iPad on a Google Doc I shared with the class, I take time to have each group share their question. We discuss each question together and decided if the question helped us understand how the external parts of this plant help it survive.
I explained to my students that creating questions that help us think deeply also help others understand our research and observations. This is a continued practice through every investigation that we do and an excellent strategy to help them master the standard fully.
I asked, what could we do to help us understand carnivorous plants better and add to our fact page in our science note book? Why, research of course!
This plant eats what?
Research for Understanding:
Through these sites, students took another glimpse at carnivorous plants and gathered more notes of interesting facts. I asked them to make a list of four "fast facts" and sketch in their science notebook of the external parts of one or two more carnivorous plants and note exactly what those external parts do.
I handed each group a card with the following questions on them then I roved and checked each group, monitoring that the discussion was on task.
Small Group Conference:
Discussion questions in small group:
What surprised you about one of the plants?
What external parts do you think are the most fascinating?
How do these external parts help each of the species you researched? ( Each of you choose one plant from your research to discuss.)
When all the research was complete and four fast facts had been compiled between them within their table groups, it was time to share. I used Google Docs. Students were able to log into the shared document and then enter their team's four fast facts. Then, when it was all complete, sharing it on the SB whole class was a snap! It led to rich discussion and really supported our knowledge about external plant parts and carnivorous plants. When we were finished,it was an easy transition into closure with an assignment for homework!
Homework: My monster plant
Before administering the directions for their assignment, I wanted them to share some "aha" moments with me. This is the moment in the lesson where students can relate their discoveries and it brings a cohesiveness or commonality that brings all the excitement back to Earth...yet often enhances the joy. We took a few moments to share.
Monster plant? A cool assignment! This little clip shows my rationale behind this assignment and how the things around me inspire me to teach NGSS standards. Lily Monsters in my own backyard are a great example for ideas for my student's designs!
Delivering the Assignment: I tell my students that they have had the chance to understand that plant parts are created to help them survive in their environment. I pass out the Rubric Carnivorous Plants to go over while I assign the homework. This rubric will help them understand the assignment and set a goal.
The assignment: Create your own "Monster Plant" ( a carnivorous plant) with external parts that help the plant get food. You may use the research and understanding you have derived from your reading and from the experiment with the Venus fly trap. Be sure that your plant exhibits line symmetry. Draw it on a sheet of white paper or use magazines to cut out parts of other plants to combine to make your own. Remember: It must be carnivorous!
Then, write a short paragraph arguing why the plant's parts function to help this plant survive in its environment. Things to consider in your plants environment are the following: Soil, climate, & predators as well as prey. You need to explain its environment and all of its external parts that help it survive in this environment. The only limitation on your creativity is that the parts must be realistic and the plant may not eat humans. We don't want to be too gross! ( Or copy "Little Shop of Horrors.")