Biology 9700/05 May June 2005 | Cambridge AS Level Past Papers With Mark Scheme

1. Light-dependent photosynthesis investigation: DCPIP reduction to track electron transport, impact of light exposure on dye color change, and control variables like temperature and buffer use.

2. Photosynthesis buffer components: sucrose preventing osmotic shock, maintaining cell structure integrity, and pH stabilization for optimal enzyme activity.

3. Human blood composition: red-to-white blood cell ratio determination, structural drawings of erythrocytes, phagocytes, and lymphocytes, and diameter measurement for cellular comparisons.

4. Experimental reliability improvements: replicates for DCPIP reduction rate, consistent light intensity for photosynthesis, and accurate timing mechanisms to enhance result precision.

5. Application of ice-cold solutions: enzyme activity control to prevent premature reaction rates and maintain experimental consistency.