sat-dog

Choice C is the best answer because it most logically completes the text’s discussion of accelerated flowering in A. thaliana plants. The text indicates that A. thaliana plants show accelerated flowering at high temperatures. To investigate the mechanism for this accelerated flowering, biologists replaced the ELF3 protein in one group of A. thaliana plants with a similar protein found in another plant species that doesn’t show accelerated flowering. The team then compared these modified plants to A. thaliana plants that retained their original ELF3 protein. The text states that the two samples of plants showed no difference in flowering at 22° Celsius, but at 27° Celsius the unaltered plants with ELF3 showed accelerated flowering while the plants without ELF3 didn’t. If accelerated flowering at the higher temperature occurred in the A. thaliana plants with ELF3 but not in the plants without the protein, then ELF3 likely enables A. thaliana to respond to increased temperatures. Choice A is incorrect because the text doesn’t mention whether any plants other than A. thaliana and stiff brome show temperature-sensitive flowering, so there is no support for the idea that this type of flowering is unique to A. thaliana. Choice B is incorrect because the text discusses the effects of ELF3 and not the production of it. There’s nothing in the text to suggest that the amount of ELF3 in A. thaliana varies with temperature. Choice D is incorrect. While the text states that there was no difference in the flowering of modified and unmodified A. thaliana plants at 22° Celsius, there’s no suggestion that A. thaliana only begins to flower at 22° Celsius; the text doesn’t mention a specific temperature threshold required for A. thaliana flowering. 11 SAT PRACTICE TEST #10 ANSWER EXPLANATIONS SAT ANSWER EXPLANATIONS n READING AND WRITING: MODULE 1