Biology 9700/43 Oct Nov 2017 | Cambridge AS Level Past Papers With Mark Scheme

1. Biodiversity assessment at genetic, species, and ecosystem levels, highlighting phenotypic variation in whale populations and challenges in accurate population size measurement.

2. Impact of industrial activities, chemical bioaccumulation (DDT, PCBs), and harmful algal blooms on whale populations, focusing on saxitoxin's neurotoxic effects.

3. Role of NADP in the light-independent stage of photosynthesis and the effect of light wavelength on the Hill reaction rate using DCPIP as a hydrogen acceptor.

4. Population dynamics of red and grey squirrels, with specific focus on virus transmission, ecological niche competition, and predator-mediated natural selection.

5. Genetic modification in Bt cotton to incorporate Cry1Ac protein for pest resistance, economic and environmental comparisons with non-GM cotton, and breeding strategies for drought-resistant Bt varieties.

6. Neural transmission enhancements via myelin sheath and mechanisms of neurotransmitter release, emphasizing acetylcholine at synapses.

7. Chemiosmosis in ATP synthesis, including mitochondrial proton gradient generation, oxygen's role as the terminal electron acceptor, and the inner mitochondrial membrane's structural adaptations.

8. Genetic and physiological impacts of galactosaemia, mutation effects on the GALT gene, and probabilities of inheritance patterns based on parental genotypes.

9. Mammalian homeostasis through negative feedback mechanisms for blood glucose regulation and thermoregulation, involving vasoconstriction, shivering, and hormonal responses.

10. Adaptive strategies in submerged plants like rice and high-temperature CO2 fixation in C4 plants such as maize or sorghum, enhancing photosynthesis efficiency.