Biology 9700/51 Oct Nov 2017 | Cambridge AS Level Past Papers With Mark Scheme

1. Investigation of urease activity, preparation of urea solutions, serial dilutions, identification of variables, and determination of Km values at different temperatures using conductivity as a measure of reaction rate.

2. Graphical representation of substrate concentration effects on reaction rates, identification of optimum temperature from Km values, and understanding enzyme-substrate affinity changes with temperature.

3. Study of salt tolerance in barley varieties X and Y, including germination under varying salt concentrations, standardized variables, identification of anomalies, and statistical correlation analysis.

4. Conclusions about salt concentration effects on barley germination, comparison of variety performance, and planning further investigations for assessing barley suitability in saline soils.

5. Application of statistical tests like Spearman’s rank correlation to evaluate germination data, with justification based on correlation strength between salt concentration and germination rates.