Education Standards
Green Leaves - Grade 7
Overview
Middle school lessons utilize local phenomenon and are organized by grade bands. By designing instruction around local phenomenon, students are provided with a reason to learn shifting the focus from learning about a disconnected topic to figuring out why or how something happens. #Going 3D with GRC
Lesson - Structure and Function of Plant Cells
Student Science Performance
Phenomenon: Leaves are darker on the top as compared to the underside.
Gather:
Students explore leaves by going outside to collect two leaves from 3-5 different plants.
Students observe leaves carefully and look for patterns across all of the leaves.
Class Discussion about Patterns
3. Students develop questions to obtain information about the patterns they observe of leaves being a different shade of green on the top than on the bottom.
Class Discussion about good Questions
4. Students obtain information from reliable sources to use as evidence for how the structure of the leaf structure functions to meet the needs of the plant.
(Teaching Suggestions: Step 3 is an opportunity for informal formative assessment as students are developing questions. Monitor the types of questions students are developing and if they will yield information that supports understanding of the basic structure of the leaf and what causes the green color in the leaf. Provide clear and actionable feedback as needed. Prompt students to gather evidence about basic leaf structure including a cross-section of a leaf, what causes the green color of the leaf, the function of the chloroplast in the leaf cells (short video showing streaming of chloroplasts in aquatic plants. This website can provide evidence for the difference in the wavelengths of light that is absorbed or reflected https://harvardforest.fas.harvard.edu/leaves/structure#absorb. See appendix B-2.)
Reason:
5. Students construct explanations supported by evidence for the causes of leaf coloration including the leaf structure and function.
6. Students develop a model to explain the relationship between the structures within the leaf and the difference in green shading between the top and bottom of the leaf.
Class Discussion:
Q: What structure of plant cells cause coloration in the leaf?
Q: How do the changes in the leaf structures cause the differences in the color?
Q: What is the relationship between cellular plant structures and food production?
Q: Why is energy input important to cells of the leaf?
(Teaching Suggestions: In this section provide insights into the focus of the class discussion. The questions are typically how, why, or what causes. This is a good place to prompt with crosscutting concepts. Build on the language students use to help them use accurate language.)
7. Students revise and use their model to support an explanation for how a cell as a whole and ways the parts of the cell contributes to the function.
Communicate Reasoning:
8. Students develop an argument for how the evidence they have gathered supports the explanation that the structure of the leaf functions to meet the needs of the plant.
(Teaching Suggestions: Students should bring into the discussion the parts of the plant - chloroplasts that function to do photosynthesis. Cells with the most chloroplasts are going to be located near the top of the leaf where sunlight penetrates the leaf. )
*See attached document below for full lesson.
Additional Lessons can be found at #Going 3D with GRC (Gathering, Reasoning and Communicating). Original authors were: Lance Nishimura, Jamie Rumage, and Jackie Sampsell