Biology 9700/02 Oct Nov 2008 | Cambridge AS Level Past Papers With Mark Scheme

1. Defense mechanisms of phagocytes and plasma cells: structural differences, engulfing pathogens, and antibody secretion roles.

2. Tuberculosis treatment challenges: multi-antibiotic regimens to prevent resistance and ensure pathogen eradication in slow-growing bacteria.

3. Water transport in plants: movement via apoplast, symplast, and transmembrane pathways; adaptations in Nerium oleander for reduced transpiration.

4. Enzyme activity and nucleotide coding: lysozyme structure, mRNA codon-amino acid relationships, and glycosidic bond hydrolysis in bacterial walls.

5. Double circulation in mammals: artery wall thickness for high pressure, pre-capillary sphincters regulating flow, and tissue fluid formation in capillaries.

6. Nitrogen cycle roles: nitrogen fixation, nitrification, decomposition, and denitrification processes connecting atmospheric nitrogen to biological molecules.

7. Malaria vaccine difficulties: antigenic variation in Plasmodium falciparum, haploid and diploid chromosomal stages, and global prevalence in tropical regions.