Biology 9700/21 May June 2013 | Cambridge AS Level Past Papers With Mark Scheme

1. Examining capillary adaptations for exchange, comparing blood, tissue fluid, and lymph compositions, and analyzing red blood cell roles in carbon dioxide transport.

2. Exploring measles virus transmission and antibody functions, highlighting specific roles of variable and constant regions in immune response.

3. Analyzing transpiration's inevitability due to gas exchange, studying environmental effects on transpiration rates, and identifying leaf adaptations for water conservation.

4. Investigating DNA structure, enzyme roles in HIV infection, differences in inhibitor actions, and the rationale for combination drug therapies in HIV treatment.

5. Understanding cell surface membrane structures, the fluid mosaic model, and the necessity of aquaporins for water transport in cells.

6. Examining cancer development through uncontrolled cell division, evidence linking smoking to lung cancer, and global mortality trends in lung cancer rates.