Biology 9700/42 May June 2019 | Cambridge AS Level Past Papers With Mark Scheme

1. Saltatory conduction mechanisms, nerve impulse transmission effects, and the impact of calcium ion channel blockers in synaptic signaling.

2. Environmental influence on fish phenotypes in captive breeding, genetic expression analysis using microarrays, and adaptive inheritance of traits related to immunity and wound healing.

3. Genetic engineering for herbicide resistance in GM soybeans, comparative implications of GM and non-GM soybean cultivation on yield and ethical considerations.

4. Mutations in the TYR gene affecting melanin biosynthesis, genetic inheritance of OCA1A, and population genetics explaining high OCA incidence in isolated populations.

5. Ultrafiltration in the kidney, factors influencing glomerular filtration rate, and cellular adaptations for selective reabsorption in the proximal convoluted tubule.

6. Evolutionary progression of light receptor complexity in eyes, convergent evolution in octopus and mammalian eyes, and molecular evidence linking shared ancestry between distantly related species.

7. Steps of oxidative phosphorylation in mitochondria, including roles of ATP synthase, the electron transport chain, and coenzymes in cellular respiration.

8. Investigations into the effects of temperature on photosynthesis rates and the strategies for restoring degraded habitats to improve ecological balance.