Biology 9700/13 Oct Nov 2013 | Cambridge AS Level Past Papers With Mark Scheme

1. Cristae in mitochondria providing large surface area for enzymatic reactions in energy production.

2. Limitations of electron microscopes including vacuum requirements and dehydration of biological specimens.

3. Importance of nucleoli for ribosome production and protein synthesis in cells.

4. Characteristics of prokaryotic cells including small size, circular DNA, and 70S ribosomes.

5. Role of sucrose solution in maintaining structural integrity of mitochondria during extraction.

6. Basic unit of cellulose; β-glucose molecules linked by 1,4 glycosidic bonds.

7. Haemoglobin's oxygen-carrying capability through reversible iron bonding and conformational changes.

8. Formation of peptide bonds between amino and carboxyl groups in amino acids during protein synthesis.

9. Influence of cholesterol on cell membrane fluidity and permeability under varying temperatures.

10. Osmosis directions based on sucrose solution concentrations; water movement towards lower water potential regions.

11. Goblet cell structure with high numbers of Golgi apparatus, mitochondria, and ribosomes for mucus production.

12. Arterial damage due to nicotine leading to plaque formation; appearance differences in smoker versus non-smoker arteries.

13. Transpiration benefits in plants for maintaining water potential and enabling stomatal function for gas exchange.

14. Challenges in vaccine development for pathogens with antigenic variation; immune response complexities with antigen changes.