Biology 9700/22 May June 2018 | Cambridge AS Level Past Papers With Mark Scheme

1. Identifying organelles in spongy mesophyll cells and calculating actual cell dimensions using photomicrographs.

2. Water transport via apoplastic pathway in leaves, highlighting water properties influencing movement and transpiration dynamics.

3. Historical discoveries in DNA structure, emphasizing Chargaff’s base-pairing rules and structural implications for inheritance.

4. Cell wall differences between Gram-positive and Gram-negative bacteria, mechanisms of antibiotic resistance, and porin protein functionality.

5. Analyzing mitotic stages and transcription activity in interphase, and explaining absence of visible nuclei in some cells.

6. Health benefits of quitting smoking, improvements in oxygen transport, and cardiovascular recovery associated with reduced nicotine and carbon monoxide levels.