Biology 9700/52 March 2020 | Cambridge AS Level Past Papers With Mark Scheme

1. Investigating the action spectra of green, brown, and red seaweeds using methylene blue and chloroplast suspensions to evaluate photosynthetic efficiency under different wavelengths.

2. Comparing chloroplast pigments in various seaweeds using thin layer chromatography and analyzing absorption data to determine light utilization in deeper waters.

3. Analyzing Parkinson's disease prevalence across age groups using graphical data and evaluating the application of Spearman’s rank correlation for age-disease relationship testing.

4. Experimenting with neural stem cell treatments in Parkinson's disease model rats, assessing dopamine concentration changes post-treatment with and without Chinese herbal drugs.

5. Evaluating the role of chloroplast pigment variations in photosynthesis efficiency at different water depths based on wavelength absorption and light penetration.

6. Standardizing and controlling experimental variables in Parkinson's disease studies, including evidence evaluation for treatment efficacy and limitations.