Biology 9700/04 May June 2005 | Cambridge AS Level Past Papers With Mark Scheme

1. ATP molecular structure: phosphate groups, ribose sugar, and adenine base; role in energy transfer via hydrolysis releasing stored energy.

2. Meiosis processes: crossing-over in homologous chromosomes during prophase I, genetic variation sources, and chromosomal independent assortment.

3. Reflex arc function: stimulus detection, sensory and motor neuron roles, and unidirectional nerve impulse flow mechanisms.

4. Dicotyledonous leaf structure: stomata function in photosynthesis, guard cell adaptations for pore regulation, and visible structural features.

5. Calvin cycle: RuBP carboxylation, photophosphorylation product utilization, and RuBP-GP concentration changes under reduced CO\\(_2\\).

6. Plant hormones: auxins in apical dominance suppression of lateral growth; gibberellins stimulating seed germination in cereal grains.

7. Natural selection importance: variation enabling adaptation; isolating mechanisms (geographical, reproductive) driving speciation and biodiversity.