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Edexcel IGCSE Biology · Spec 2.17

Diffusion and Non-Living Membrane Practicals

Covers investigate diffusion using agar cubes, Investigate osmosis through a non-living membrane and Identify variables, measurements and improvements.

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Diffusion and Non-Living Membrane Practicals

Spec 2.17

What you need to know

  • Investigate diffusion using agar cubes
  • Investigate osmosis through a non-living membrane
  • Identify variables, measurements and improvements

Active recall

Quick check

Answer each question before opening the answer.

What does the agar-cube investigation demonstrate?

Diffusion and the effect of surface area-to-volume ratio

Why must Visking tubing be blotted before weighing?

To remove external water that would falsely increase the measured mass

Why calculate percentage mass change?

It allows samples with different starting masses to be compared fairly

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