Biology 9700/42 May June 2023 | Cambridge AS Level Past Papers With Mark Scheme

1. Glycolysis pathway overview, including ATP production via substrate-level phosphorylation, pyruvate transport into mitochondria, and the link reaction.

2. Chromosomal behavior during meiosis I, detailing stages like prophase, metaphase, anaphase, and telophase, and the role of cytokinesis in gamete formation.

3. Natural selection in Plectritis congesta populations; winged versus wingless fruit traits, evidence supporting species classification, and new trait emergence via mutations.

4. Genetic technology applications in restriction enzyme production, database utility for enzyme study, and electrophoresis versus chromatography technique comparisons.

5. Hardy-Weinberg principle applied to calculate rat population genetics under warfarin resistance; advantages of dominant versus recessive allele frequency increases.

6. Glomerular filtration rate (GFR) influenced by age, sex, and other physiological factors; processes of selective reabsorption in nephrons.

7. Effects of temperature on muscle contraction efficiency; tetrodotoxin impact on motor neuron function by altering sodium channel structure.

8. Photosynthesis rates linked to rubisco activity; Calvin cycle dynamics including TP use and RuBP regeneration in GM versus non-GM crops.

9. Endocrine system roles, hormonal targets, and feedback mechanisms regulating glucose levels post-meal.

10. Zoo conservation roles beyond breeding; challenges of captive breeding, and assisted reproduction techniques like IVF for species like the black rhinoceros.