Biology 9700/42 March 2019 | Cambridge AS Level Past Papers With Mark Scheme

1. Investigation of light intensity on photosynthesis rate using a pond plant, sodium hydrogencarbonate, and capillary tube setup.

2. Hormonal regulation of blood glucose via glucagon, detailing receptor activation, enzyme cascades, and glucose transport mechanisms.

3. Immune response through B-lymphocyte activation, transcription factor roles in plasma and memory cell differentiation, and microarray applications.

4. Natural selection driving phenotype changes in Mexican spadefoot toad tadpoles under variable detritus and algae availability.

5. Expansion of GM crop cultivation across the USA, Brazil, India, and China, including benefits of pest resistance in Bt maize.

6. MELAS syndrome inheritance via mitochondrial DNA and mtDNA's role in evolutionary studies through mutation analysis.