Biology 9700,22 Oct Nov 2024 | Cambridge AS - A Level Past Papers With Mark Scheme

1. Triglycerides and Fatty Acid Composition | Identification of saturated and unsaturated fatty acids in olive oil, structure of triglycerides, and their regional variation in composition.

2. Water as a Solvent and Phloem Transport | Explanation of water’s solvent properties for polar molecules, insolubility of triglycerides, and role of phloem in transporting organic substances.

3. HIV Transmission and Opportunistic Infections | Control measures for HIV prevention, classification of Pneumocystis jirovecii as a fungus, and structural features distinguishing it from bacteria.

4. Pathogenesis and Cellular Interactions | Adhesion of P. jirovecii to alveolar epithelial cells, its impact on oxygen transport, and inhibition of fungal enzymes as a treatment strategy.

5. Molecular Biology of Transcription | Complementary base pairing between DNA and RNA nucleotides, missing phosphodiester bonds, and structural identification of nucleotide pairs.

6. Stem Cells and Cellular Differentiation | Role of mitosis in tissue repair, telomere function in maintaining genetic integrity, and differentiation pathways of haematopoietic stem cells.

7. Malaria and Oxygen Transport | Effect of Plasmodium infection on red blood cells, rightward shift in oxygen dissociation curves, and how this impacts oxygen loading and unloading.

8. Water and Mineral Ion Transport in Plants | Apoplast and symplast pathways in root water transport, role of the Casparian strip, and active vs. passive transport mechanisms for potassium ions.