Biology 9700/23 May June 2013 | Cambridge AS Level Past Papers With Mark Scheme

1. Features of palisade mesophyll cells, vacuole width calculation, fluid mosaic structure of the tonoplast, and water movement into vacuoles.
2. In vitro translation process for protein synthesis, cellular requirements for high protein activity, mRNA specificity, and translation efficiency in vitro vs. in vivo.
3. Nitrogen cycle processes (e.g., nitrogen fixation, nitrification), contributions of organic material to soil nitrogen, and phosphate-nitrogen roles in ecosystems with high energy flow.
4. Enzyme-catalyzed reaction monitoring, catechol oxidase activity, competitive inhibition effects, and the role of acids like citric acid in slowing enzymatic browning.
5. Importance of mitosis for growth and repair, MPF protein structure and function in prophase, and consequences of MPF persistence during anaphase.
6. Distinction between infectious and lifestyle diseases, measles pathogen and transmission, and factors contributing to resurgence in measles cases.