Biology 9700/43 Oct Nov 2019 | Cambridge AS Level Past Papers With Mark Scheme

1. Mechanisms of guard cell function under water stress, including the role of abscisic acid and ion transport.

2. Homologous chromosome identification, meiosis importance, and implications of random gamete fusion in recessive allele expression.

3. Applications of recombinant DNA technology in therapeutic protein production, including advantages and plasmid properties.

4. Natural selection in Magellanic penguins linked to environmental factors like food availability and reproductive success correlations.

5. Isolating mechanisms between Mimulus species based on pollination differences and post-zygotic isolation in hybrid sterility.

6. Effects of heavy metal ions like cadmium and copper on photosynthesis, focusing on photosystem II and chlorophyll structure changes.