Biology 9700/42 Oct Nov 2011 | Cambridge AS Level Past Papers With Mark Scheme

1. Speciation of Ethiopian wolves through geographic isolation; low heterozygosity due to small pack sizes and inbreeding.

2. Dipstick tests for glucose detection: glucose oxidase and peroxidase enzymatic reactions, cellulose acetate layers for selective permeability.

3. Blood glucose and renal threshold comparison; glucose reabsorption limitations in renal tubules leading to glycosuria.

4. Gametogenesis in humans: spermatogenesis differences from oogenesis; testosterone's endocrine function in regulating FSH and LH suppression.

5. Rice adaptation to submersion: ethene and gibberellin interaction via snorkel genes SK1 and SK2 for elongation response in deepwater rice.

6. Gene therapy for LCA using adenovirus vectors, trial limitations, and modifications to viral genomes for safe therapeutic use.

7. Glycolysis pathways: glucose conversion, hexose bisphosphate roles, anaerobic pyruvate fermentation, and energy production in yeast cells.

8. Insulin production using recombinant DNA technology; steps in gene insertion, vector transformation, and host screening for industrial synthesis.

9. Asthma triggers and genetic prevalence; ESE3 gene mutation leading to excessive collagen, with high incidence in Tristan da Cunha inhabitants.