Activity 3.5: Evidence-Based Arguments about Plants (50 min)

Show slide 3 of the 3.5 Evidence-Based Arguments Tool for Plants PPT. Show students the final section, beginning around 6:20, of the Growing Plants Video to review both plant investigations with students.

• This video was produced when the Carbon TIME Plants Unit used vermiculite instead of plant gel. You may need to help students make connections between the data presented in the video with the vermiculite and the data students investigated with the plant gel or paper towel.

Display slide 4 of the 3.5 Evidence-Based Arguments Tool for Plants PPT. Draw students’ attention to the Class Results 11 x 17 Posters from the investigations (3.3 & 3.4) and students’ own Observing Plants Worksheets (from 3.2 & 3.4), section D, “Results for the whole class.” Ask the students to find a partner, and in their own words, review what happened during the investigations. Tell them to discuss:

• What patterns they observed in the mass change
• What patterns they observed in the BTB color change

Tell students that when scientists construct arguments for what happened, using evidence from observations is important, so today’s activity is designed to help them use the evidence from the investigation to construct an argument for “what happens when plants are in the light and dark” and "what happens when plants grow" come to class consensus.

Display slide 5 of the 3.5 Evidence-Based Arguments Tool for Plants PPT. Pass out one copy of 3.5 Evidence-Based Arguments Tool for Plants to each student. Review Tool directions. Also, have students take out their Three Questions Handout and be ready to refer to their class results.

• Instruct students to complete their evidence, conclusions, and unanswered questions as individuals for the Three Questions.
• Give students about 5-10 minutes to complete the process tool.

Display slide 6 of the 3.5 Evidence-Based Arguments Tool for Plants PPT. Divide students into pairs.

• Have each pair compare their evidence, conclusions and unanswered questions for the Matter Movement Question.
• Have partners discuss how their ideas are alike and different. Have students change or add to their responses, based on partner input.
• Have students repeat this step for the Matter Change Question and the Energy Change Question.
• As students are sharing, circulate through the groups. Consider asking questions such as, How does this (refer to students’ evidence and/or conclusions) help us better understand the Matter Movement Question (or substitute one of the other Three Questions)? What questions do you still have at the atomic-molecular level to better understand this phenomenon?
• Pay attention to patterns in students’ ideas. You will want to begin moving towards class consensus in this activity.
• Partner work should take about 10 minutes.

Display slide 7 of the 3.5 Evidence-Based Arguments Tool for Plants PPT.

• Have students/pairs share their evidence and conclusions for the Matter Movement question. Keep a class record, using the PPT slides or board. Ask students to update their answers by using a different colored writing utensil. Discussions should move toward class consensus. Use class conversation to correct student ideas. Use the Three Questions Handout to help guide towards consensus by following the established rules.
• Have students share unanswered questions. Discussions should move toward class consensus. Use the 3.5 Assessing the Evidence-Based Arguments Tool for Plants to guide your goals for consensus. Note that students may contribute unanswered questions that align with rules on the Three Questions Handout, but may not closely align with those on the Assessing worksheet. You may still choose to record those unanswered questions. These may be answered in other parts of this unit or even in other units during the school year. However, at this point in this unit, though there may be several viable paths of inquiry moving forward, you will begin to more closely guide the path of inquiry in one direction – in this case towards molecular modeling of photosynthesis.
• Class discussion should take about 10 minutes.

Display slide 8 of the 3.5 Evidence-Based Arguments Tool for Plants PPT.

• Class discussion may take another 10 minutes

Display slide 9 of the 3.5 Evidence-Based Arguments Tool for Plants PPT.

• Class discussion may take another 10 minutes

Display slide 10 of the 3.5 Evidence-Based Arguments Tool for Plants PPT.

• Use the Unanswered Questions to set the stage for students’ next steps, specifically the need to know what’s happening at the atomic-molecular scale.
• Take a moment to show students that you have arrived at the “top of the triangle” on the instructional model poster. This means they will be making a transition. When they went “up the triangle,” they conducted an investigation and collected evidence based on what they could observe using their own eyes and also tools (e.g., macroscopic observations). Now they are preparing to go “down the triangle,” when they will figure out how to explain what happened in the investigations at an atomic-molecular scale by being provided and practicing with a model for scientifically-accurate thinking.

Display slide 11. Tell students that they will revisit their unanswered questions later in the unit to see which questions they can now answer. Save the PPT slides with the class’s unanswered questions and/or take a picture of them for later.

Show slide 12 of the 3.5 Evidence-Based Arguments Tool for Plants PPT.

• Conclusions: What did you observe during the investigation?
• Predictions: How do you think the plants gained more mass than the paper towel lost?
• On a sheet of paper or a sticky note, have students individually answer the exit ticket questions. Depending on time, you may have students answer both questions, assign students to answer a particular question, or let students choose one question to answer. Collect and review the answers.

The conclusions question will provide you with information about what your students are taking away from the activity. Student answers to the conclusions question can be used on the Driving Questions Board (if you are using one). The predictions question allows students to begin thinking about the next activity and allows you to assess their current ideas as you prepare for the next activity. Student answers to the predictions question can be used as a lead into the next activity.

Show slide 13 of the 3.5 Evidence-Based Arguments Tool for Plants PPT.

• Pass out a Learning Tracking Tool for Plants to each student.
• Have students write the activity chunk name in the first column, "Investigating Plants" and their role, "Investigator."
• Have a class discussion about what students did during the activity chunk. When you come to consensus as a class, have students record the answer in the second column of the tool.
• Have a class discussion about what students figured out during the activity chunk that will help them in answering the unit driving question. When you come to consensus as a class, have students record the answer in the third column of the tool.
• Have a class discussion about what students are wondering now that will help them move towards answering the unit driving question. Have students record the questions in the fourth column of the tool.
• Have students keep their Learning Tracking Tool for future activities.
• Example Learning Tracking Tool