Biology 9700/12 May June 2013 | Cambridge AS Level Past Papers With Mark Scheme

1. Microscope magnification calculations, identification of prokaryotic and eukaryotic cell features, and chloroplast structural analysis.

2. Biochemical properties of amino acids, lipid detection via emulsion test, and glycosidic bonds in carbohydrates like glycogen and amylose.

3. DNA replication limits due to telomeres, mitotic processes ensuring genetic stability, and nucleotide pairing affecting hydrogen bond counts in DNA.

4. Translocation in sieve tube elements, adaptations in halophytes, and tissue organization in major blood vessels like arteries.

5. Cardiac cycle pressure changes, Bohr effect influencing oxygen dissociation from haemoglobin, and heart structural adaptations in aortic stenosis.

6. Nitrogen cycle stages involving denitrification, nitrification, and ammonification; energy flow in ecosystems and limiting effects of nitrogen on trophic transfer.