Biology 9700/42 March 2024 | Cambridge AS Level Past Papers With Mark Scheme

1. Nephron structural identification and role of proximal convoluted tubule in selective reabsorption.

2. Genetic basis of Mendel's stem length experiments in peas; gibberellin's role in plant growth and internode elongation.

3. Cystic fibrosis genetics explored through Hardy-Weinberg principle, life expectancy trends, and ethical considerations in genetic testing.

4. Impact of heat stress on milk yield in cattle; genetic adaptation through SLICK allele introduction via selective breeding and gene editing.

5. Photosynthetic response to light wavelengths; DCPIP color change as a measure of light-dependent reaction efficiency.

6. Germination inhibition by blue light in barley linked to abscisic acid (ABA) and its effect on gibberellin synthesis.

7. Muscle contraction mechanisms involving troponin, tropomyosin, actin, and myosin; succinylcholine as a neuromuscular blocker.