Biology 9700/21 May June 2019 | Cambridge AS Level Past Papers With Mark Scheme

1. Antibody molecular structures, secondary and tertiary structural features, hybridoma cell production, and monoclonal antibody applications in disease treatment.

2. Role of unsaturated fatty acids in phospholipid adaptation to cold, structural differences between triglycerides and phospholipids, and thromboxane-mediated arterial constriction as cell signaling.

3. Enzyme activity assays using absorbance, effects of copper sulfate and potassium sulfate on Neutrase® activity, and benefits of immobilized enzymes for industrial applications.

4. Meristematic tissue division and differentiation into sieve tube elements and companion cells, their structures, and roles in phloem transport.

5. Closed and double circulation in mammals, structural adaptations of the heart chambers, and coordination of cardiac cycle contractions.

6. DNA nucleotide composition calculations, other locations of DNA in grasshopper cells, and the functional roles of tRNA regions during translation.