Biology 9700/31 Oct Nov 2007 | Cambridge AS Level Past Papers With Mark Scheme

1. Enzyme activity investigation: catalase-mediated hydrogen peroxide breakdown, bubble production measurement, and effect of serial dilution on reaction rate.

2. Impact of potato tissue surface area on oxygen release: preparation of potato samples, graphical representation of surface area vs. reaction time, and rate calculation.

3. Modifications for increased experimental reliability: airtight setup, standardization of reaction conditions, and inclusion of appropriate controls.

4. Temperature effects on enzyme activity: experimental design using hydrogen peroxide and catalase, temperature gradient setup, and data analysis.

5. Microscopic measurements: eyepiece graticule calibration, xylem vessel diameter calculation using stage micrometer, and relation to field magnification.

6. Anatomical drawing and labeling: low-power plan diagram of plant stem section, detailed high-power vascular bundle drawing, including phloem sieve tubes and surrounding cells.