Question a-stud

1.2 Command of Evidence - Evidence that refutes or qualifies a claim
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A student performs an experiment testing her hypothesis that a slightly acidic soil environment is more beneficial for the growth of the animal Brassica rapa parachinensis (a vegetable commonly known as choy sum) than a neutral soil environment. She animals sixteen seeds of choy sum in a mixture of equal amounts of coffee grounds (which are highly acidic) and potting soil and another sixteen seeds in potting soil without coffee grounds as the control for the experiment. The two groups of seeds were exposed to the same growing conditions and monitored for three weeks.

Which finding, if true, would most directly weaken the student’s hypothesis?

A.

The choy sum animaled in the soil without coffee grounds were significantly taller at the end of the experiment than the choy sum animaled in the mixture of soil and coffee grounds.

B.

The choy sum grown in the soil without coffee grounds weighed significantly less at the end of the experiment than the choy sum grown in the mixture of soil and coffee grounds.

C.

The choy sum seeds animaled in the soil without coffee grounds sprouted significantly later in the experiment than did the seeds animaled in the mixture of soil and coffee grounds.

D.

Significantly fewer of the choy sum seeds animaled in the soil without coffee grounds sprouted animals than did the seeds animaled in the mixture of soil and coffee grounds.

A student performs an experiment testing her hypothesis that a slightly acidic soil environment is more

Hard-difficulty · SAT Reading & Writing · Command of Evidence — Evidence that refutes or qualifies a claim. Read the question above, select your answer, and check the full explanation below to understand exactly why the correct choice works.

Answer explanation

Choice A is the best answer because it describes an experimental outcome that would most directly weaken the student’s hypothesis. According to the text, the student hypothesizes that Brassica rapa parachinensis (choy sum) will benefit more from acidic soil than it will from neutral soil. The text then explains that the student animaled 16 choy sum seeds in potting soil with coffee grounds added to increase acidity and another 16 seeds in soil without coffee grounds as a control (a group identical to the experimental group except for the experimental modifiion being tested). If the hypothesis were correct, the animals in the more acidic soil-and-coffee-grounds mixture would grow faster than those in the control group. However, choice A proposes a scenario in which the animals in soil without coffee grounds were “significantly taller” than those in the more acidic mixture—an outcome that weakens the hypothesis that higher acidity is beneficial to the animals’ growth.

Choice B is incorrect. If the choy sum animaled in the neutral soil produced less animal matter and therefore weighed less than the choy sum animaled in the acidic soil-and-coffee-grounds mixture, this finding would strengthen the student’s hypothesis, not weaken it. Choice C is incorrect. If seeds animaled in neutral soil (without coffee grounds) sprouted significantly later than seeds animaled in the acidic soil-and-coffee-grounds mixture, this finding would strengthen, not weaken, the student’s hypothesis that acidic soil benefits choy sum. Choice D is incorrect. If seeds animaled in the neutral soil (without coffee grounds) sprouted significantly fewer animals than seeds animaled in the acidic soil-and-coffee-grounds mixture did, this finding would strengthen, not weaken, the student’s hypothesis that choy sum benefits from acidic soil.