Biology 9700/43 May June 2020 | Cambridge AS Level Past Papers With Mark Scheme

1. Genotype and phenotype inheritance in courgettes; cross-pollination of Golden Dawn and Tondo di Piacenza varieties; unexpected F1 fruit phenotype explanation; F2 phenotype ratio.

2. Sterility of triploid watermelons due to genetic incompatibility; resistance transfer methods for watermelon mosaic virus (WMV) from Cucurbita ecuadorensis.

3. Speciation mechanisms in Ficedula albicollis and F. hypoleuca; hybrid sterility and sperm viability analysis; role of pre-zygotic and post-zygotic isolation.

4. Cystic fibrosis effects on mucus viscosity; prenatal and IVF screening advantages; double screening methods for genetic and chromosomal abnormalities.

5. Gene regulation in yeast under glucose and galactose conditions; function of Mig1 transcription factor; metabolic engineering for lactose utilization in yeast.

6. Calvin cycle intermediate synthesis in photosynthesis; element requirements for amino acid production; structural and functional roles of photosynthetic compounds.