Biology 9700/31 May June 2020 | Cambridge AS Level Past Papers With Mark Scheme

1. Serial dilution of 1.0% invertase solution to prepare a series of lower concentrations, including stepwise calculations and correct labeling of test-tubes.

2. Measurement of time taken for Benedict’s solution to show a color change when mixed with invertase solutions and honey extract, determining enzyme concentration.

3. Analysis of sucrose concentration reduction over time in stored honey, graphical representation of data, and identification of sugars remaining after 25 weeks with biochemical reasoning.

4. Drawing of a plan diagram of a plant stem section, including labeling of epidermis and xylem vessel elements in vascular bundles, with attention to proportionality.

5. Calculation of actual stem diameter from a scaled photomicrograph, including proper unit conversion and step-by-step methodology.

6. Comparison of anatomical features between plant stems of terrestrial and aquatic species, identifying adaptive features for aquatic living.