#20 - Antarctic seals dive to great depths and stay

[sarae]

I understand why B is correct, but why is A incorrect? Although it does provide support that "they don't rely solely on oxygen held in their lungs.." the question stem asks for support for the hypothesis, which is found in the last sentence about seals.

Thanks!

[Steve Stein]

Hi sarae,

Good question! In that example, the question is a Strengthen Except question, meaning that all of the answer choices provide some support for the hypothesis presented except for one (the correct answer choice is the one that does not provide support).

To review,the hypothesis is that the seals in question store oxygen in their spleens when submerged on long dives.

Answer choice A is an incorrect answer choice, as you noted, which means that it will strengthen the researchers' hypothesis. That choice provides that horses can accomplish this feat, which does provides support by showing that spleen-based oxygen storage has been shown to be possible in other species.

I hope that's helpful! Please let me know whether this is clear--thanks!

~Steve

[sarae]

makes sense, thanks!

[brettb]

Are there any other reasons for eliminating A?

I felt like B provided as much support as A, and it seemed like assumptions had to be made about both of them.

As I was reading A I was thinking in order for A to offer support we have to assume that what is true of horse spleens is also true of seal spleens. It seemed like this was too far reaching of a jump to assume what is true of one animal must then be true of another animal.

As I read B I was thinking in order for B to support we have to assume if many species of seal can store oxygen in their muscles then perhaps they can store oxygen in other part of their body as well. This seemed like less of an assumption and less of a stretch than A.

Looking at it I can see where the test writers were going with it, but if I saw this scenario again I'm not confident I would be able to correctly select.

[Claire Horan]

Hi Brett,

The incorrect answer choices will provide SOME amount of support for the hypothesis, even if it is a small amount of support. The correct answer choice will be the one that provides no support or actually weakens the hypothesis.

You say, "As I was reading A I was thinking in order for A to offer support we have to assume that what is true of horse spleens is also true of seal spleens. It seemed like this was too far reaching of a jump to assume what is true of one animal must then be true of another animal." Strictly speaking, you do not have to "assume" that what is true of horse spleens is also true of seal spleens. You do not have to assume anything at all. Instead, the fact that horses, which are mammals along with seals, are able to store oxygens in their spleens suggests that seals might also be able to do so. You are right to say that this does not strengthen the hypothesis a lot, or as much as the other incorrect answer choices, but it does strengthen the argument somewhat.

B, on the other hand, could properly be considered to be either irrelevant or to weaken the hypothesis. Either the other species can store oxygen in their muscles and antarctic seals can't (which would be irrelevant because it doesn't address what antarctic seals can do) OR antarctic seals can also store oxygen in their muscle tissues (which would decrease the need for them to store it in their spleens, potentially weakening the spleen-storage hypothesis). You can think of B as presenting an alternative mechanism for storing oxygen rather than providing supporting the spleen hypothesis.

I hope this helps!

-Claire
PowerScore LSAT and GRE Instructor

[gwlsathelp]

Just to clarify, the conclusion of this question is the last sentence: "some researchers hypothesize that for long dives these seals also store oxygenated blood in their spleens"?

[Adam Tyson]

Technically it's not a conclusion, gwlsathelp, because there is no argument in the stimulus, just a hypothesis, which is only a proposed explanation. There were no premises in the stimulus used to support that claim, so it cannot be considered a conclusion.

The stem asks us to support the hypothesis rather than strengthen an argument or support a conclusion, so we just need evidence that would make that hypothesis seem more likely to be correct. For our purposes it works the same way as if that were a conclusion, though, so to some extent you are absolutely correct!

[ikim10]

I know that LSAC considers "common knowledge" to be fair game on the LSAT, but I missed this question because I didn't know that spleens were not a type of muscle tissue. My general understanding is that a spleen is an organ in the human body, and organs are made of muscle tissue. Can someone explain how we were expected to know this deduction? Because of this, I ended up choosing (C), because at least if the oxygen in the lungs and blood were inadequate, then it could imply that oxygen is stored somewhere else.

[Luke Haqq]

Hi ikim10!

This is a strengthen/except question, so four of the answer choices will strengthen the stimulus, while the correct answer will not do so.

Answer choice (C) strengthens the researchers' hypothesis. Researchers "hypothesize that for long dives these seals also store oxygenated blood in their spleens." This is beyond the oxygen stored in their lungs and blood. If the oxygen they had in their lungs and blood was insufficient to support seals on their long dives, as (C) supposes, this reinforces that they must be getting their oxygen from elsewhere--in that respect, it strengthens the hypothesis that they contain extra reserves of oxygen someplace else, such as their spleen.

[CJ12345:]

Hi, Powerscore,
In a situation in which I don't understand the meaning of "spleens", is there any way to get the right AC? When doing this Q, I thought the spleen might be a type of muscle tissue thus not choosing B.