Biology 9700/01 May June 2005 | Cambridge AS Level Past Papers With Mark Scheme

1. Prokaryotic cell identification: DNA in circular form, differences from eukaryotic cells, and lack of membrane-bound organelles.

2. Protein structure and enzymatic activity: effects of pH, temperature, and inhibitors on secondary and tertiary structure, with graph interpretation for reaction rates.

3. Membrane transport mechanisms: facilitated diffusion, active transport, osmosis, and impacts of ion gradients on cellular processes.

4. Circulatory system adaptations: closed double circulation in mammals, valve functionality during systole, and skeletal muscle roles in venous return.

5. Gas exchange: alveolar structure differences in smokers with emphysema, reduced oxygen transport due to tobacco smoke, and disease implications.

6. Nitrogen cycle and fertilizers: roles of nitrifying and nitrogen-fixing bacteria, alternatives to chemical fertilizers, and ecosystem contributions of legumes.

7. Immune responses: primary vs. secondary antibody production, memory cell activation, and roles of lymphocytes in adaptive immunity.

8. Community ecology: definition encompassing all organisms in an area, interspecies interactions, and ecological roles in food webs.