Biology 9700/03 Oct Nov 2006 | Cambridge AS Level Past Papers With Mark Scheme

1. Leaf transpiration investigation using leaves coated with petroleum jelly on different surfaces to analyze water loss and stomatal activity under varying conditions.

2. Preparation and microscopic examination of leaf impressions using nail varnish to assess stomatal density and structure.

3. Comparison of stomatal density on upper vs. lower leaf surfaces using eyepiece graticules and calculation of stomatal index.

4. Differences in transpiration rates based on leaf treatment: freshly picked, petroleum jelly coating variations, and time since harvest.

5. Experiment enhancements: controlled variables like humidity, temperature, and leaf size for more accurate transpiration measurement.