Biology 9700/12 Oct Nov 2015 | Cambridge AS Level Past Papers With Mark Scheme

1. Ribosomal size in mitochondria (70S) and its comparison to eukaryotic and prokaryotic cells.

2. Characteristics of lysosomes: single membrane, hydrolytic enzyme content, and function in organelle recycling.

3. Benedict’s and acid hydrolysis tests for reducing and non-reducing sugars, interpretation of precipitate mass.

4. Identification of polysaccharides like glycogen and cellulose based on glycosidic bond type.

5. Temperature-sensitive enzymes in metabolic pathways: tyrosinase activation and its effect on rabbit fur color.

6. Osmotic balance in plant tissue, water potential equilibrium, and red blood cell lysis in hypotonic solutions.

7. Casparian strip role in root water transport, active loading of sucrose into phloem, and water potential changes.

8. Oxygen dissociation curve shifts due to 2,3BPG, affecting hemoglobin affinity and oxygen unloading.

9. Effects of smoking on cardiovascular and respiratory health, including risks of COPD, emphysema, and lung cancer.

10. Soil fertility reduction in waterlogged conditions due to denitrifying bacteria converting nitrate to nitrogen gas.