Biology 9700/35 May June 2023 | Cambridge AS Level Past Papers With Mark Scheme

1. Investigation of the effect of salt concentration on water movement in potato discs, using proportional dilutions of 1 mol dm⁻³ salt solution and measuring total disc length changes.

2. Analysis of osmotic effects, estimating the salt concentration at which no net water movement occurs, and proposing procedural improvements for accuracy.

3. Comparison of salt content in processed and unprocessed foods, including percentage increase calculations and identification of the independent variable.

4. Plan diagrams and detailed drawings of vascular bundles and leaf cross-sections, emphasizing structural differences between aquatic and terrestrial plants.

5. Calibration of an eyepiece graticule using a stage micrometer and application of calibration data to calculate the thickness of a leaf section.

6. Identification of plant adaptations like large air spaces in aquatic leaves, highlighting their role in buoyancy and gas exchange.