Biology 9700/23 May June 2010 | Cambridge AS Level Past Papers With Mark Scheme

1. Structural identification in animal cells, focusing on organelles viewed under an electron microscope, their functions, and limitations of electron microscopy compared to light microscopy.
2. Cardiac cycle coordination and structural adaptations in the heart, emphasizing the myogenic nature of cardiac muscle and differences in wall thickness between ventricles and atria.
3. Protein structure analysis in insulin, focusing on disulfide bonding and peptide bond hydrolysis mechanisms.
4. Malaria control strategies, challenges in vaccine development, and comparative efficacy of drugs on chloroquine-sensitive and chloroquine-resistant strains of Plasmodium falciparum.
5. Nitrogen fixation and urease-mediated hydrolysis of urea in the nitrogen cycle, highlighting the role of competitive inhibitors and experimental control design in enzyme activity studies.
6. Human gas exchange system adaptations for efficient oxygen and carbon dioxide exchange, effects of tar on respiratory tissues, and the significance of elastic fibers in alveolar function.