Checking for understanding
When students have collected their data in the red pepper osmosis experiment, how will you check whether they understand what has happened?
Explaining the movement of water in osmosis requires students to clearly order their thoughts, and is a good opportunity for you to check for misconceptions.
Students could be asked to work together to annotate their results graph using key terms such as: osmosis, diffusion, water molecules, sucrose solution, dilute solution, concentrated solution, concentration gradient, concentration, percentage increase in mass, percentage decrease in mass, no change in mass, flaccid, turgid, cells, tissue, into the cell, out of the cell.
Alternatively, you could ask students to draw a diagram of a test tube of sucrose solution containing a piece of red pepper tissue in each of the three zones of the graph, with arrows to indicate net movement of water molecules.
How else might you check students’ conceptual understanding of what is happening during this practical?
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