Biology 9700/06 May June 2005 | Cambridge AS Level Past Papers With Mark Scheme

1. Intestinal epithelial cells: villi adaptations for digestion and glucose absorption, inhibition effects of phlorrhizin on active transport, and peppermint oil’s impact on calcium ion-dependent smooth muscle contraction.

2. Human ear structure: semicircular canals' role in balance, effects of glue ear causing temporary hearing loss, and sound wave transmission challenges.

3. Nervous system and heart rate regulation: contrasting effects of sympathetic and parasympathetic nerve stimulation on sinoatrial node (SAN) via neurotransmitter actions.

4. Liver lobule functions: plasma protein secretion, fibrinogen's role in blood clot formation, and prevention of tissue fluid accumulation through osmotic pressure regulation.

5. Microbial applications: genetic organization in bacteria, bioremediation of crude oil by anaerobic bacteria from whale stomachs, and isolation techniques for pure bacterial cultures.

6. Genetic mutations and inheritance: chloroquine resistance in Plasmodium falciparum, gene mutation effects on protein synthesis, and significance of inbreeding in increased infection susceptibility.

7. Down’s syndrome and neural tube defects: genetic and structural chromosomal abnormalities, methyl group metabolism effects, and statistical evidence for genetic links between conditions.

8. Plant genetics: dihybrid test-cross analysis in tomatoes, observed phenotype ratios deviating from Mendelian expectations due to linked gene recombination.