Biology 9700/21 Oct Nov 2011 | Cambridge AS Level Past Papers With Mark Scheme

1. Identification and labeling of key membrane components: protein channels, receptor sites, phospholipid heads, and cholesterol.

2. Endocytosis mechanisms in cell membranes, including vesicle formation for bacterial uptake and intracellular digestion.

3. Catalase enzymatic breakdown of hydrogen peroxide into oxygen and water; initial reaction rate calculation and oxygen volume analysis over time.

4. Copper ion effects on catalase activity; comparative analysis of enzyme efficiency under varied hydrogen peroxide concentrations.

5. Description of protein structural organization in haemoglobin: primary, secondary, tertiary, and quaternary levels.

6. Structural and functional comparison between haemoglobin and collagen; role of collagen in arterial walls.

7. Investigation of anti-cancer drugs’ effectiveness on tumour growth; vinblastine's role in spindle apparatus disruption during mitosis.

8. Phloem transfer cell adaptation for sucrose movement; sucrose translocation from source to sink in plants.

9. Immune response roles of phagocytes and lymphocytes, focusing on antigen recognition and removal of non-self substances.