Biology 9700/43 May June 2024 | Cambridge AS Level Past Papers With Mark Scheme

1. Focus on osmoregulation mechanisms, including the role of ADH and genetic conditions like neurogenic diabetes insipidus, affecting kidney function.

2. Genetic and environmental factors influencing phenotypic variation, explored through examples like tomato yield, strawberry size, and human traits such as resting heart rate.

3. Analysis of epistasis in plant genetics, exemplified by gene interactions affecting malvidin production in Primula petal coloration.

4. Discussion of genetic engineering techniques, highlighting the roles of enzymes like restriction endonuclease, DNA ligase, and reverse transcriptase, as well as practical applications in insulin production.

5. Role of BRCA2 as a tumor suppressor gene in DNA repair; implications of mutations like 999del5 in breast cancer risk and the significance of genetic screening programs.

6. Environmental and genetic regulation of stomatal movement in plants, mechanisms of photosynthesis, and mitochondrial roles in cellular respiration.