Biology 9700/42 May June 2020 | Cambridge AS Level Past Papers With Mark Scheme

1. Mechanism of action and homeostatic role of ADH in response to decreased blood water potential.
2. Genetic cross and inheritance patterns in squash plant fruit shapes, including genotypes and meiosis-related processes.
3. Gene flow concerns from GM squash plants to wild relatives and implications on social and environmental levels.
4. Factors contributing to the extinction of tiger subspecies and genetic analysis using mitochondrial DNA for evolutionary studies.
5. Challenges and immune system considerations in selecting vectors for gene therapy.
6. Molecular mechanisms of muscle contraction involving calcium ions, troponin, and tropomyosin in thyrotoxic myopathy.