Biology 9700/33 Oct Nov 2013 | Cambridge AS Level Past Papers With Mark Scheme

1. Lipase activity investigation using triglycerides in milk as substrate, effect of varying substrate concentration, and endpoint detection with color indicator.

2. Preparation of triglyceride concentrations via simple dilution, raw and processed data recording, and calculation of lipase activity rate.

3. Control setup for lipase experiments, identification of experimental errors, and differences in endpoint time between milk types.

4. Plan diagram of plant leaf cross-sections, detailed xylem vessel drawings, and calculations of chloroplast density per mm² using photomicrographs.

5. Analysis of single-celled freshwater organisms, food web trophic level determination, and structural comparison with plant cells.