Biology 9700/06 Oct Nov 2004 | Cambridge AS Level Past Papers With Mark Scheme

1. Retina structure and color perception: cone cell acuity, rhodopsin absorption spectra, and mutations causing red-green color blindness linked to X-chromosome genes.

2. Muscle contraction mechanisms: myosin role in sarcomere shortening, biceps relaxation by antagonist triceps, and ATP-driven cross-bridge cycling.

3. Bile salt function: fat emulsification, liver synthesis pathways, and reabsorption in enterohepatic circulation with fecal loss calculation.

4. Neurological control in gymnastics: cerebellum for balance and coordination, medulla oblongata in autonomic regulation, and Alzheimer's disease impact on brain tissue.

5. Bacteriophage counting: plaque assay technique, serial dilution reliability, and calculating phage concentration in original samples.

6. Seed bank protocols: dormancy breaking treatments, germination conditions, and periodic seed regeneration to maintain viability.

7. Down’s syndrome diagnosis: genetic basis in trisomy 21, screening methods' detection rates, and improvements to prenatal testing accuracy.