Page 11 18. Resveratrol is a substance which may reduce the risk of heart disease. Using recombinant DNA technology, E. coli bacteria have been modified so that they now produce resveratrol when grown in a medium containing coumaric acid. The graph shows concentrations of resveratrol and coumaric acid in the medium over a 30 hour period. 30 25 20 15 10 5 0 220 200 180 160 140 120 100 80 60 40 20 0 110 100 90 80 70 60 50 40 30 20 10 0 Coumaric acid concentration (mg/l) Resveratrol concentration (mg/l) Time (hours) The simplest whole number ratio of the concentration of resveratrol to coumaric acid after 25 hours is A 1 : 2 B 1 : 40 C 10 : 1 D 20 : 1. 19. Which row in the table identifies how the bottleneck effect and habitat corridors may change genetic diversity of a population? Change in genetic diversity Bottleneck effect Habitat corridors A decrease decrease B decrease increase C increase decrease D increase increase [Turn over