Biology 9700/31 Oct Nov 2023 | Cambridge AS Level Past Papers With Mark Scheme

1. Investigation of temperature effects on CO₂ production in yeast, using hydrogencarbonate indicator to monitor enzymatic activity in glucose breakdown.

2. Yeast growth inhibition by copper ions, demonstrating enzyme inhibition and its implications for fermentation equipment material choice.

3. Plant stem structure analysis, focusing on vascular bundle composition and xylem vessel arrangement through microscopic examination and diagramming.

4. Estimation of stomatal density on plant leaves using photomicrographs and mathematical calculations to evaluate gas exchange capacity.

5. Comparative analysis of leaf structures from different plants, linking structural differences to environmental adaptations like water conservation or gas exchange efficiency.

6. Emphasis on procedural accuracy in biological investigations, including improved sample analysis and controlled experimental setups.