Choice C is the best answer. The previous question asks what
potential criticism might be made of Volkov’s testing of Hodick and
Sievers’s model. The answer, that a central element of that model
wasn’t corroborated by Volkov’s measurements, is best supported
in the last paragraph: “This made the trap close without any direct
touch to its trigger hairs (while they didn’t measure calcium levels,
the current likely led to increases).” Because the physical touch to the
hairs figured in Hodick and Sievers’s model, it can be said that Volkov’s
decision to apply an electrical current directly to the plant means that
he failed to corroborate a central element of their model.
Choices A, B, and D are incorrect because the cited lines don’t support
the answer to the previous question. Instead, they summarize the
basic agreement of Volkov’s work with Hodick and Sievers’s model
(choice A) and describe steps in Volkov’s experimental design that
are related to the application of an electrical current but don’t directly
address the omission of the central element of the physical touch to the
hairs (choices B and D).
QUESTION 52
Choice C is the best answer. The second sentence of the last
paragraph says that the focus of Volkov’s work was the role of
electricity in the Venus flytrap’s closing mechanism. The paragraph
goes on to explain that by applying electricity directly to the plant
and “altering the amount of electrical current, Volkov could determine
the exact electrical charge needed for the trap to close.” It is therefore
accurate to say that Volkov and his colleagues made the most extensive
use of information obtained from measuring the plant’s response to
varying amounts of electrical current.
Choice A is incorrect because although the last paragraph explains
that Volkov’s work was based on Hodick and Sievers’s mathematical
model in which an electrical charge is required to close the Venus
flytrap, that model isn’t described as predicting the precise amount of
charge required; moreover, although Volkov made use of this earlier
model, it served as a starting point, and his work made greater use
of the findings generated by his experiment. Choice B is incorrect
because the passage doesn’t describe Volkov’s work as having
involved analysis of data from earlier studies on the plant’s response to
electricity. Choice D is incorrect because although the last paragraph
explains that Volkov based his work on Hodick and Sievers’s earlier
model, this was the sole model that Volkov relied on, and there is
no suggestion that he made use of multiple “published theories”
or “earlier models”; moreover, he made more extensive use of data
generated by his own experiment than of Hodick and Sievers’s model.