Biology 9700/53 May June 2012 | Cambridge AS Level Past Papers With Mark Scheme

1. Pollen germination and tube growth across different media containing varying concentrations of boric acid, calcium nitrate, magnesium sulfate, and potassium nitrate.

2. Mean pollen tube lengths and percentage germination over time, with statistical analysis using t-tests to determine significant differences between growth media.

3. Role of calcium and sucrose in germination and tube elongation; evidence-based conclusions regarding their differential effects.

4. Experimental design involving inside-out intestine bags to study sugar absorption, impact of respiratory inhibitors, and glucose vs. fructose uptake rates.

5. Active transport and diffusion mechanisms in nutrient absorption, with quantitative assessment of relative absorption rates under varying conditions.