Biology 9700/04 Oct Nov 2003 | Cambridge AS Level Past Papers With Mark Scheme

1. Photosynthesis in sun vs. shade leaves: differences in carbon dioxide uptake rates at varying light intensities, light saturation in shade leaves, and effects of temperature increases on photosynthetic efficiency.

2. Role of NAD in respiration: reduction during glycolysis and Krebs cycle, inability to regenerate NAD in anaerobic conditions, and glycolysis rate increase in yeast under anaerobic respiration.

3. Blood glucose regulation: changes post-glucose intake, insulin secretion in response to elevated glucose, and glucagon’s role in maintaining glucose levels during hypoglycemia.

4. Warfarin resistance in rats: inheritance patterns of resistance alleles, natural selection maintaining 50% resistance, and survival challenges for homozygous dominant individuals requiring excessive vitamin K.

5. Liver functions: Kupffer cells breaking down hemoglobin into bilirubin, hepatocytes deaminating excess amino acids, and detoxification processes for compounds like alcohol via enzymatic breakdown.