Biology 9700,33 Oct Nov 2024 | Cambridge AS - A Level Past Papers With Mark Scheme

1. Enzyme Activity and Ethanol Effects | Investigation of catalase activity in potato cylinders, effect of ethanol on enzyme function, and measurement of foam height as a proxy for reaction rate.

2. Experimental Design and Serial Dilution | Preparation of ethanol dilutions, accuracy in volume measurements, and impact of ethanol concentration on enzyme activity.

3. Data Recording and Analysis | Tabulating and graphing enzyme activity data, calculating reaction rates, and interpreting trends over time.

4. Error Identification and Experimental Improvements | Recognizing sources of error in enzyme assays, distinguishing between systematic and random errors, and proposing modifications for improved reliability.

5. Polyphenol Oxidase and Fruit Browning | Effect of ethanol on PPO activity in wampee fruits, analysis of experimental results, and explanation of enzymatic oxidation inhibition.

6. Microscopy and Plant Stem Analysis | Drawing detailed plan diagrams of plant stem sections, measuring vascular bundles, and comparing structural differences between plant specimens.