Biology 9700/42 May June 2012 | Cambridge AS Level Past Papers With Mark Scheme

1. Disruptive selection in seahorses, maintaining extremes in phenotypes due to size-based mating preferences.
2. Monoclonal antibodies for syphilis diagnosis, emphasizing specificity to T. pallidum and fluorescent tagging.
3. Gel electrophoresis in DNA sequencing, focusing on nucleotide identification via fragment separation.
4. Genetic modification in Golden Rice™ to increase β carotene production for addressing vitamin A deficiency.
5. Effectiveness of HIV prevention in Uganda through ARV usage and contraception to reduce vertical transmission.
6. Relationship between plant biodiversity and climate, highlighting the role of mean annual rainfall in species richness.