Biology 9700/32 Oct Nov 2008 | Cambridge AS Level Past Papers With Mark Scheme

1. Observation of osmotic effects of potassium nitrate and lead nitrate on onion epidermal cells and recording cellular changes in distilled water, T1, and T2 solutions.
2. Evaluation of experimental errors in microscopy-based observations, including light adjustment and specimen preparation inconsistencies.
3. Plasmolysis investigation using sodium chloride concentration gradients, with graph plotting and anomaly identification to refine the hypothesis.
4. Plan and high-power drawings of animal and plant tubular structures for comparative analysis, emphasizing lumen width and structural adaptations.
5. Measurement techniques using eyepiece graticules and stage micrometers to calculate actual dimensions, highlighting potential sources of measurement errors.
6. Comparison and contrasting of animal and plant tubular structures, recording visible differences in organization and identifying plant-specific features like cell walls.
7. Representative cell drawings to illustrate diversity in size and shape within plant tissue, with emphasis on accurate selection and marking of cells for analysis.