Biology 9700/43 May June 2011 | Cambridge AS Level Past Papers With Mark Scheme

1. Conservation biology of the natterjack toad (Bufo calamita), factors leading to endangerment, and population trends analyzed through annual counts.

2. Industrial enzyme applications: immobilized papain activity comparison, advantages in stability and reuse, and methods for enzyme immobilization in alginate.

3. Ovarian follicle anatomy and the impact of contraceptives on ovulation; gene-blocking methods targeting ZP3 for hormone-free contraception.

4. Hybrid maize production: advantages of hybrid vigor, challenges in seed production, and adaptations to reduce photorespiration under hot, dry conditions.

5. Genetic modification in Bt maize: ecological impacts on caddis fly species, potential effects of Bt toxin on aquatic ecosystems, and critiques of experimental studies.

6. Krebs cycle intermediates and oxidative phosphorylation processes, focusing on ATP generation in mitochondria.

7. Meiosis stages reordering, mechanisms of genetic variation in offspring, and natural selection principles in population dynamics.

8. Huntington’s Disease inheritance: gene mutation explanation, dominant allele effects, and genetic probability analysis for offspring outcomes.

9. Photosynthesis processes: light-dependent stage generating reduced NADP, and Calvin cycle utilization of NADPH for carbon fixation.

10. Plant hormones: abscisic acid's role in stomatal closure and gibberellin's function in seed germination.