Leaf Disc Photosynthesis Differentiated Biology High School Inquiry Lab Carbon and Energy Cycling

Your students are about to watch photosynthesis happen in real time.

In this floating leaf disc lab, students pull the air out of spinach discs, drop them in sodium bicarbonate solution, and time how fast they rise as oxygen builds up inside the leaf. Faster floating means faster photosynthesis, and students will have actual data to measure the rate. It's hands-on, a little bit magical, and it runs on spinach, baking soda, and a light.

What Students Investigate

Students test how carbon dioxide concentration and temperature affect the rate of photosynthesis. Then they use their data to write a CER and build a lab poster. You can test both variables in one class or split them across three classes. Both setups are mapped out for you. This lab is part of my full unit on Climate Change where students investigate if planting more trees can solve the current climate crisis.

One Lab, Three Levels

Every student runs the same experiment, so your whole class can compare data during the gallery walk.

• Honors: Null and directional hypotheses, t-test analysis, and a design-your-own experiment
• Academic: ET50 analysis, graphing, and a group CER
• Scaffolded: Visual lab overview, vocabulary table, checklist procedure, pre-numbered graph, and CER sentence frames

What's Included

• 8-page teacher guide with lesson plans for two 45-minute class periods, a full supply list, solution recipes, troubleshooting tips, and grading notes
• Honors, Academic, and Scaffolded student handouts
• Lab poster rubrics for Honors and Academic/Scaffolded
• Lab day PowerPoint with procedures for sinking the leaf discs, safety reminders, and a lab cleanup checklist
• 3 Excel templates: class data, group data, and sample data (in case your spinach has an off day)

Standards Alignment

• NGSS HS-LS1-5: Use a model to illustrate how photosynthesis transforms light energy into stored chemical energy
• SEPs: Developing and Using Models, Analyzing and Interpreting Data, Constructing Explanations
• CCCs: Energy and Matter, Cause and Effect

Perfect For

• High school biology, AP Biology prep, and environmental science
• Photosynthesis and cell energy units
• Climate change units (this lab is part of the Keystone Science Unit 6 Climate Change curriculum, but it works in any biology course)

Want the full story? Pair this lab with the NGSS Biology Climate Change Unit to help students answer the big question: can planting more trees solve climate change?

Leaf Disc Lab Preview