Biology 9700/03 May June 2002 | Cambridge AS Level Past Papers With Mark Scheme

1. Osmosis experiment: potato strip length changes in sucrose solutions of varying concentrations; mean change calculations to determine solute potential of potato cell sap.

2. Graph analysis: plotting mean length changes against sucrose concentration to infer the concentration where no net water movement occurs.

3. Osmotic movement at equilibrium: water movement ceases as internal and external solute potentials are equalized.

4. Experiment reliability improvements: consistent strip lengths, precise measurement tools, and longer immersion times for equilibrium.

5. Aorta transverse section: labeled plan drawing showing tissue layers; explanation of thick walls for pressure endurance and smooth inner lining reducing turbulence.

6. Magnification calculation: use of scale bars and measured drawing dimensions to determine the magnification factor.