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Command of Evidence SAT question

Reading and Writing · Information and Ideas · Hard · Answer it here, explanation included.

Tadpole Body Mass and Toxin Production after Three Weeks in Ponds

Population densityAverage tadpole body mass (milligrams)Average number of distinct bufadienolide toxins per tadpoleAverage amount of bufadienolide per tadpole (nanograms)Average bufadienolide concentration (nanograms per milligram of tadpole body mass)
High193.8722.695,815.51374.22
Medium254.5621.655,525.72230.10
Low258.9722.084,664.99171.43

Ecologist Veronika Bókony and colleagues investigated within-species competition among common toads (Bufo bufo), a species that secretes various unpleasant-tasting toxins called bufadienolides in response to threats. The researchers tested B. bufo tadpoles’ responses to different levels of competition by creating ponds with different tadpole population densities but a fixed amount of food. Based on analysis of the tadpoles after three weeks, the researchers concluded that increased competition drove bufadienolide production at the expense of growth.

Which choice uses data from the table to most effectively support the researchers’ conclusion?

ExplanationShow

Choice B is the best answer. This data shows that the tadpoles in the high-density pond (meaning those with the most competition) didn’t grow as big as the other two groups but produced more bufadienolide.

Choice A is incorrect. This doesn’t fully support the conclusion. It doesn’t include any data about bufadienolide production. Choice C is incorrect. This doesn’t fully support the conclusion. It doesn’t include any data about growth. Choice D is incorrect. This doesn’t fully support the conclusion. It doesn’t demonstrate that the tadpoles in the high-density pond produced more bufadienolide overall. The fact that they didn’t produce more kinds of bufadienolide isn’t relevant to the conclusion.

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