Biology 9700/22 Oct Nov 2019 | Cambridge AS Level Past Papers With Mark Scheme

1. Identification and function of phloem sieve tubes and tissue layers in the stem of Ranunculus repens, including preparation of diagrams and use of microscopy for correct tissue proportions.

2. Analysis of the effects of smoking on the gas exchange and cardiovascular systems, with data interpretation on tar, nicotine, and CO content across WHO regions and its impact on blood oxygen supply.

3. Comparative study of erythroblast and mature red blood cells, with a focus on organelle involvement in protein synthesis and implications of spherocytosis mutations on oxygen transport and water potential effects.

4. Examination of polymer structures in biological molecules, differentiation of glucose polymers, and explanation of DNA semi-conservative replication involving nucleotide polymerization.

5. Investigation of antibiotic use and its impact on malaria transmission dynamics, including mosquito gut immunity, bacterial competition, and implications for disease management in high-malaria regions.

6. Role of telomerase in chromosome stability, enzyme action theories, and substrate concentration effects on reaction rates, with relevance to stem cells, cancer cells, and enzymatic flexibility.