This question is a bit tougher, and you will need to look now at the tubes grown in low light in order to answer it. Look carefully at the differences between growing the bacteria in low light and growing the bacteria in the high light. It does not make very much difference in the wild type (LH1+, LH2+, RC+). That strain grows well in either low or high light. It also does not make much difference in the mutant where the RC gene is not working right (LH1+, LH2+, RC-), since this mutant does not grow under either condition. However, LH1+, LH2-, RC+ (which has a broken LH2) does not grow quite as well at low light as the normal bacteria do and LH1-, LH2+, RC+ (which has a broken LH1) grows very poorly in low light. What do you think these two genes might be doing? They help the bacterium to change color in the light so that they can attract other bacteria. They act like the funnel on the machine, collecting light energy and giving it to the reaction center. They keep the bacterium from getting hurt by too much light

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