Question 8
A scientist designs an experiment to investigate effects of light on red algae and bacteria aggregation. After illuminating a filament of red algae with light that passed through a prism, thus exposing different segments of algae to different wavelengths of light, the scientist added aerobic bacteria and then noted in which areas the bacteria congregated. The scientist noted that the largest groups were found in the areas illuminated by the red and blue light. In addition to the above, the scientist also set up 4 experimental groups in parallel. I Red algae not exposed to the white light II Red algae not exposed to the white light and then added the aerobic bacteria III Red algae exposed to the white light directly without passing through prism IV Red algae exposed to the white light directly without passing through prism and then added the aerobic bacteria For questions 8.1 and 8.2, choose experimental groups I, II, III and /or IV 8.1 Which is the positive control group? ______________________ (1 point) 8.2 Which is the negative control group? ______________________ (1 point) 8.3 What is the explanation for the congregation of bacteria in the red and blue areas? (write down ✓if correct or ✗ if wrong) (2 points) 8.3.1 These areas had the highest pH 8.3.2 These areas had the most N2 being produced. 8.3.3 These areas had the most CO2 being consumed. 8.3.4 These areas had the most oxygen being released.