Biology 9700/35 Oct Nov 2014 | Cambridge AS Level Past Papers With Mark Scheme

1. Preparation of serial dilutions for yeast suspension concentrations; use of methylene blue as an indicator for enzyme activity.

2. Observations of color changes indicating enzyme activity; factors influencing accuracy in measuring color intensity and suggestions for methodological improvements.

3. Investigation of lactose hydrolysis by immobilized enzymes; effects of contact time on hydrolysis percentage and graph plotting of experimental data.

4. Microscopic examination of onion epidermal cells; comparative staining using iodine and methylene blue to identify cellular components.

5. Photomicrograph analysis of mammalian organ sections; feature identification supporting absorption functions and plan diagram illustration of projections.

6. Calculation of ratios for structural widths in organ sections using magnified images; preparation of observational records comparing specimens from different mammals.