Biology 9700/22 Oct Nov 2023 | Cambridge AS Level Past Papers With Mark Scheme

1. Examination of chromosome behavior and structural changes during interphase, S phase, and prophase in the mitotic cell cycle.

2. Analysis of keratin stability in feathers, focusing on protein structural features such as α-helices, β-pleated sheets, and disulfide bonds.

3. Keratinase enzyme activity assessed across varying temperatures and pH levels, with applications in industrial processes like feather degradation and detergent formulations.

4. Study of liver cell functions, highlighting Kupffer cells in phagocytosis, detoxification by hepatocytes, and the role of peroxisomes in oxidative reactions.

5. Mechanisms of gas exchange and ventilation in alveoli, emphasizing elastic fibers, surfactant production, and diffusion gradients.

6. Exploration of TB transmission, immune responses leading to latent infections, and structural vulnerabilities in elastic arteries linked to M. tuberculosis infection.

7. Xylem adaptations for water transport in plants, including lignification, tension maintenance, and cellular modifications to minimize flow resistance.