Biology 9700/51 Oct Nov 2010 | Cambridge AS Level Past Papers With Mark Scheme

1. Leaf adaptations to sunlight vs. shade: differences in internode length, leaf mass, surface area, and water loss rates; comparative surface area-to-mass ratios for shaded and sun-exposed leaves.

2. Statistical analysis using t-tests to determine significance in internode length and leaf surface area-to-mass ratio between conditions; calculation of degrees of freedom and critical value interpretation.

3. Structural adaptations in shaded vs. exposed leaves: differences in cuticle thickness, chloroplast distribution, and leaf anatomy observed through transverse sections.

4. Investigation of temperature effects on crustacean heart rates: controlled variables (e.g., specimen size, acclimatization time), raw data conversion to percentage changes, and assessment of temperature's impact on heart rate trends.

5. Evaluation of the hypothesis that heart rate doubles with every 10°C increase, identification of anomalies at higher temperatures, and prediction of heart rate decline at extreme heat.

6. Calculation methods for percentage change in heart rate and experimental refinements to improve accuracy and reliability in biological investigations.