PT57, S3, Q24 It is widely believed that lancelets

by **giladedelman** Wed Jul 07, 2010 5:30 pm

24. (C)
Question Type: Assumption
The author bases his conclusion that the lancelet’s contracting vessel is a heart on two premises: 1) it resembles the structure of other sea animals’ hearts, and 2) its contractions resemble the contractions of other animals’ hearts. If we assume that a vessel that meets these two conditions qualifies as a heart, then we must agree with the argument. Answer (C) expresses that assumption.

(A) is out of scope. It sets a parameter for those animals that may have hearts, but doesn’t provide any criteria by which to judge whether a particular vessel is a heart.
(B) is irrelevant. Whether some other primitive animals have hearts has no bearing.
(D) reverses necessary and sufficient conditions. It would be correct if it said, "Any vessel that undergoes muscular contractions can be properly considered a heart."
(E) is a bit like (A), describing a characteristic of animals with hearts, but not addressing the essential characteristics of the heart itself.