Biology 9700/43 Oct Nov 2018 | Cambridge AS Level Past Papers With Mark Scheme

1. Conservation biology focus on Bali starling (Leucopsar rothschildi), addressing causes of population decline, zoo-based protection roles, and genetic biodiversity risks in small populations.

2. Analysis of genetic crosses in Drosophila melanogaster, including statistical tests, phenotypic ratios, test crosses, and linkage effects on observed versus expected offspring distributions.

3. Meiosis mechanisms contributing to genetic variation, the role of crossing over, and natural selection illustrated by herbicide resistance in Amaranthus tuberculatus, supported by experimental data and t-test statistical analysis.

4. Study of speciation and biodiversity in Mecyclothorax beetles across Hawaiian islands, analyzing factors influencing species density, habitat fragmentation effects, and evolutionary processes on Haleakalā volcano.

5. Gene therapy in treating Leber’s congenital amaurosis (LCA), detailing recombinant DNA creation, vector delivery methods, implications of autosomal recessive inheritance, and viral vector optimization for therapeutic applications.

6. Glycolysis pathways in cellular respiration, emphasizing phosphorylation, oxidation, and ATP production steps, with comparisons of metabolic differences between cancerous and normal cells.

7. Photosynthesis mechanisms in chloroplasts, analyzing accessory pigments, wavelength effects on oxygen production, and structural-functional relationships within chloroplast compartments.

8. Nervous system signaling, including sensory receptor roles, action potential dynamics, refractory periods, and myelinated axon transmission processes, supported by graphical data on stimuli responses.

9. Detailed exploration of Bacteria domain characteristics and botanic gardens' contributions to endangered species protection, highlighting biodiversity conservation and ecological research benefits.

10. Functional adaptations of nephron structure for ultrafiltration and insulin’s effects on blood glucose homeostasis, emphasizing target tissue responses and physiological regulatory mechanisms.