Biology 9700/43 Oct Nov 2010 | Cambridge AS Level Past Papers With Mark Scheme

1. Mitosis stage identification, key structural features observed, and the biological importance of mitosis for growth, repair, and asexual reproduction.

2. Differences between DNA and RNA structures, complementary tRNA anticodon determination, and nucleotide requirements for a specific polypeptide synthesis.

3. Active transport of mineral ions in plant root hairs, phosphate role in metabolism, and water absorption mechanisms in roots, including pathways like apoplast, symplast, and vacuolar.

4. Hemoglobin oxygen transport analysis via dissociation curves; comparison of fetal and adult hemoglobin affinities and myoglobin's oxygen storage efficiency in muscles.

5. Assimilate transport in plants from source to sink; mechanisms involving phloem and adaptations like aphid feeding on phloem cells for nutrient access.

6. Nitrogen cycle stages: denitrification in anaerobic conditions, nitrate ion toxicity in drinking water, and agricultural flooding impacts on soil fertility and crop yield.