PrepTest 141, Section 2, 8. Biologist: Marine animals known…

How will the right answer fit in terms of support and conclusion?

Only the right answer will support the conclusion without bringing in anything new. It’s also totally fair (more precise but unnecessarily complicated) to say only the right answer must be true if the conclusion is true.

Highlight the main conclusion in the passage, if there is one:

eyes are adapted only to an animal’s needs rather than to some abstract sense of how a good eye would be designed.

Biologist: [BACKGROUND]. But [SUPPORT], so [INTERMEDIATE CONCLUSION]. This example shows that [CONCLUSION].

Yes, every once in a while a statement can get support and also give support to the main conclusion. The LSAT will sometimes call that an intermediate conclusion.

You should really recognize that “adapted only to an animal’s needs” is changing the subject. The rest of the passage only says how the animal’s eyes work, but says nothing about how they “adapted” and nothing about the “animal’s needs”. The right’s answer is gonna have to make that connection.

Map the wording of the answers to the wording of the passage:

(A) the only kind of jellyfish with retinas that…

Are we comparing some jellyfish to others? Definitely not. So what does this have to do with eyes adapting to an animal’s needs? Nothing.

(B) Box jellyfish have a need to detect prominent features of objects but not fine details.

Do you see how every word of this maps to the exact wording the passage used? If that’s how the jellyfish’s eyes work, and the conclusion about adapting to needs is true, then the jellyfish must have this need. Winner!

(C) …would benefit from having retinas that…

This doesn’t map to the wording of the conclusion, which was concerned with “needs”, not “benefits”.

(D) …developed from jellyfish whose…

This doesn’t connect to the “animal’s needs”, so it makes us add in our own reasoning to make sense of it. Right answers never do that.

(E) …main means of detecting prey.

Wow irrelevant. There’s nothing about prey, hunting, survival, nothing about what vision is for at all in the passage.

(B) is the correct answer.

Common pattern/s in this question: The new wording in the conclusion really helps cut through the fat in the wrong answers, so make sure you recognize when the conclusion changes the subject.

Not as important, but avoid confusion and don’t forget intermediate conclusions are out there. That’s a hybrid support-conclusion statement. But most passages don’t have one.