Biology 9700/31 May June 2024 | Cambridge AS Level Past Papers With Mark Scheme

1. Investigation of plasmolysis in onion cells by observing the effect of different sodium chloride concentrations, correlating cellular response to osmotic gradients.

2. Determination of water potential changes in plant cells, involving concepts like turgor pressure and the movement of water across membranes.

3. Practical analysis of sucrose concentration on mass change in potato pieces, linking results to osmotic balance and estimating isotonic points using graphical representation.

4. Starch detection in plant roots using iodine, applying serial dilution techniques to estimate starch concentration in seasonal root extracts.

5. Microscopic examination and comparison of structural differences in root tissues, focusing on features like vascular arrangements and cellular organization.

6. Emphasis on improving accuracy in practical experiments through refined measurements, repetition, and enhanced procedural control.