Biology 9700/43 May June 2010 | Cambridge AS Level Past Papers With Mark Scheme

1. American crocodile conservation: effect of water salinity on nesting sites, population trends post-conservation in the Everglades, and percentage increase in nesting sites.

2. FSH and LH interaction with specific receptors; cellular responses to FSH binding and target cell locations for hormone receptor specificity.

3. Antibiotic resistance in bacteria: disc diffusion method comparing penicillin V and synthetic penicillin on Gram-positive vs. Gram-negative bacteria.

4. Cereal crop significance in global nutrition; alpha-amylase activity in sorghum and rice linked to temperature, with tertiary structure explanations.

5. Genetic divergence among Drosophila species: DNA sequence comparisons, speciation due to geographic isolation, and ecological adaptations.

6. Krebs cycle and respiration: NAD reduction, hydrogen atom roles, differences in lactate and ethanol production during anaerobic respiration.

7. Gene technology applications: use of fluorescent markers, advantages of GM rice with enhanced vitamin A, and environmental risks of GM crops.