The Why Behind Teaching This:
Unit 3 addresses standards related to the transfer of energy and matter between organisms in an ecosystem. The unit begins with identifying what solar energy is and what two forms of energy solar energy provides to life on Earth. This is an important foundation for understanding standard 5-PS3-1: Use models to describe that energy in animals' food (used for body repair, growth, motion, and to maintain body warmth) was once energy from the sun. We build on this knowledge throughout the unit in other lessons related to photosynthesis and how animals use the energy they get from food. In this unit students will also be conducting experiments to gather evidence to support their belief that plants get the materials they need for growth from either water, air, or the soil. This is covered in standard 5-LS1-1: Support an argument that plants fet the materials they need for growth chiefly from air and water. Students will be creating food chains and food webs to describe the movement of matter among organisms in an ecosystem. This is covered in standard 5-LS2-1: Develop a model to describe the movement of matter among plants, animals, decomposers, and the environment.
I combined these three standards all into unit 3 because teaching them together allows students to see how they are all connected. The energy that plants get from the sun is stored in their parts until animals consume them. Plants cannot absorb this energy and reproduce without other materials from the environment such as carbon dioxide from the air, and water and nutrients from the soil. The animals that consume the plants use part of the energy for growth, reproduction, etc. but they also store some of the energy. That energy is then passed on to other animals once eaten. All of the energy that is available in an ecosystem can ultimately be traced back to the sun. Teaching all of these standards together, instead of in isolation of each other, makes that connection easier to see.
This specific lesson addresses standard 5-LS1-1: Support an argument that plants get the materials they need for growth chiefly from air and water. Through the multiple experiments that will be conducted, students will be collecting evidence to determine what is most important for plant growth. By working through the steps of the scientific method and controlling variables, standard 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved.
The goal of today's lesson is for students to gather evidence through experimentation to support their argument on what materials are most important for plant growth.
Students will demonstrate mastery of this goal by creating a presentation to share with the class stating their claim and providing evidence to support that claim.
Preparing for Lesson:
Have one copy of each of the following ready for each group:
Groups will be presenting so no materials will be needed
What Has Got Us To This Point:
Today's lesson is the concluding lesson from the "Where do Plants Get the Materials They Need: Day 1). After setting up the experiments during the day 1 lesson, students have been measuring the heights of the plants and recording the data every Friday for three weeks. Today they will be analyzing the data in their groups, making adjustments to their original thinking, and presenting the findings to the class.
Review Posters and Original Thoughts:
I begin today's lesson by showing the posters that were made during the first lesson. Each group created a poster that answered the question, "What is most important to plants for growth?". They had four picture cards to choose from: air, water, sunlight, and soil.
I pass each poster back to the group that created it so they can review what they had chosen, and the reasons they chose it, which were also recorded on the poster. I give them a few minutes to discuss their original thoughts and if they feel it is still accurate. While groups discuss, I circulate to listen to conversations and to ask questions about the conversations taking place.
Making Line Graphs:
We learned how to create bar graphs during a graphing lesson earlier in the year. The data for these experiments is plant growth over a three week period. This data would not be displayed on a bar graph, it would be displayed on a line graph. I explain to students that line graphs show change over time and since we are showing the change in growth over a three week period, then we would need to use a line graph. I take about 10 minutes to create an anchor chart for how to create a line graph with the students so they have something to refer back to when creating their graphs independently.
I have a large sheet of chart paper hanging on the whiteboard in the front of the class. I have it titled "Creating Line Graphs". I ask students what the first step is to create a graph (it is the same for bar graphs). They tell me to draw the x and y axis. I do this step at the top of the paper so that it takes up about half of the sheet. I record Step 1: Draw the x and y axis about 3 inches below that. Students tell me step two is to write the title at the top of the graph. I write How Does Water Effect The Growth Of Plants at the top and underline it. I also record Step 2: Title the Graph at the bottom. These two steps are the same for both line graphs and bar graphs. The remaining steps are different, and thus I will take over leading the completion of the anchor chart.
I explain to students that in order to create a line graph, the data will be plotted with points, and then the points connected to form a line. I ask students if they believe the measurements will go on the y-axis, as it does with a bar graph, or along x-axis at the bottom. They tell me across the bottom. I believe they chose the bottom because measurements are on the side for bar graphs and they think it would be different. I quickly draw what the graph would look like with the measurement on the y-axis, and with them on the x=axis.
I ask again, where the measurements should be, and this time they tell me on the y-axis. Giving them visuals is important because it allows them to compare the two and see why it is better to put the measurements on the side and the time the measurements are taken on the bottom. Seeing that visual will also help them when they go to create their own graphs independently.
I record Step 3: Label the y-axis with the increments for the measurements taken. I also add step four to the anchor chart, Step 4: Label the x-axis with the times the measurements were taken. The final step in creating the graph is Step 5: Plot the data with points, then connect the points to form a line. I add a note at the bottom of the chart stating that if there in more than one thing being graphed, they will need to use different colored lines and add a key.
Directions for the Activity:
I place one of the graph templates on the overhead so I can go over how to complete it with the class. Each template has space for 3 graphs. I explain to the students that they will create 3 graphs for each experiment, one for each trial. There are 2 plants for each trial, except the type of soil which has 3. I explain that they will have 2 or 3 (for types of soil) different lines on their line graph and will need to make them different colors and provide a key.
I provide each group with one set of each of the graphing templates:
I explain that each group member will be responsible for completing the graphs for one of the experiments and explaining the results during the presentation. Group members can help each other and work together but each member is responsible for one. After all graphs are complete, they will need to discuss with their group to determine which materials are most important for plant growth.
Illustrating the Data in Graphs:
Students spend the next 20 minutes of this lesson creating the graphs to illustrate the data they recorded from the experiment. I circulate to make sure students are completing the graphs correctly and to ensure that conversations taking place are focused on helping each other graph, or on the results from the experiment.
Presenting and Defending Their Arguments:
Groups begin presenting their graphs and explaining the data they recorded in each experiment. I allow students to use the overhead to show their graphs to the class while explaining their results. The graphs are rather small and without projecting them on the screen, most students would not be able to see what actually occurred in the experiment. Having students analyze the data in their graphs and relate it back to the original question "Which material is most important for plant growth?" ensures that students truly understand what the data means. It also requires them to apply the results to their original thinking about the question to determine if the results support their idea or not. After sharing their graphs with the class, they hold up the original poster they created on day one of the lesson. They state what their original thoughts were on what they believed effected plant growth the most. Then, they explain how analyzing their data has either supported their original thoughts, or led them to a new conclusion, and what that conclusion is.
I keep track of what each group states effects plant growth the most. After all groups have presented their findings and conclusion, we compare and contrast the thoughts of all groups. I ask groups what they considered when deciding what effected the growth the most. One group said which plants grew the most. Another group said which plants grew the fastest (some grew by week 1, while others did not grow until week 2 or 3). I allowed students to question each other and explain their reasoning when questioned by another group.