Biology 9700/31 Oct Nov 2019 | Cambridge AS Level Past Papers With Mark Scheme

1. Investigation of ethanol concentration effects on beetroot pigment release, preparation of proportional dilutions, and intensity observations using a color scale.

2. Identification of independent and dependent variables in ethanol experiments, explanation of ethanol's effects on beetroot membranes, and evaluation of experimental errors with suggested improvements.

3. Acoustic emission measurements of potato tissues under varying water potentials, graphical data representation, and estimation of water potential for specified acoustic values.

4. Drawing and labeling anatomical structures in stained transverse sections of plant stems, including detailed observations of specific tissue regions.

5. Calculation of mean dimensions and ratios for plant stem features using photomicrograph measurements, with steps clearly shown and whole number ratios determined.

6. Tabulation and comparative analysis of observable structural differences between plant stem specimens, emphasizing tissue organization and variations in outer layers.