LSAT Explanation PT 37, S2, Q20: Antarctic seals dive to great depths

LSAT Question Stem

Each of the following, if true, provides some support for the researchers' hypothesis EXCEPT: 

Logical Reasoning Question Type

This is a Strengthen question. 

Correct Answer

The correct answer to this question is B. 

LSAT Question Complete Explanation

First, let's analyze the argument in the passage. The passage discusses Antarctic seals and their ability to dive to great depths and stay submerged for hours. It states that they do not rely solely on oxygen held in their lungs but also store extra oxygen in their blood. The researchers hypothesize that for long dives, these seals also store oxygenated blood in their spleens. The structure of the argument is as follows:

Premise: Antarctic seals dive to great depths and stay submerged for hours.

Premise: They do not rely solely on oxygen held in their lungs but also store extra oxygen in their blood.

Conclusion (Hypothesis): For long dives, these seals also store oxygenated blood in their spleens.

An "Evaluate" question for this argument could be: "Is there any evidence that the spleens of Antarctic seals contain higher concentrations of oxygenated blood during long dives?"

Now, let's discuss the question type and what it's asking us to do. This is a Strengthen Except question, which means we need to identify the answer choice that does not provide some support for the researchers' hypothesis.

a) Horses are known to store oxygenated blood in their spleens for use during exertion.

This answer choice provides some support for the hypothesis by showing that spleen-based oxygen storage has been shown to be possible in other species, such as horses. This indicates that it might also be possible for seals.

b) Many species of seal can store oxygen directly in their muscle tissue.

This is the correct answer. This choice does not provide support for the hypothesis because it suggests an alternative mechanism for storing oxygen, rather than supporting the idea that seals store oxygenated blood in their spleens.

c) The oxygen contained in the seals' lungs and bloodstream alone would be inadequate to support the seals during their dives.

This answer choice strengthens the hypothesis by suggesting the need for an additional storage mechanism, such as storing oxygenated blood in their spleens, to support the seals during their dives.

d) The spleen is much larger in the Antarctic seal than in aquatic mammals that do not make long dives.

This answer choice provides support for the hypothesis by implying that the larger spleen in Antarctic seals could be related to their ability to store oxygenated blood for long dives.

e) The spleens of Antarctic seals contain greater concentrations of blood vessels than are contained in most of their other organs.

This answer choice strengthens the hypothesis by suggesting that the higher concentration of blood vessels in the spleens of Antarctic seals could be related to their ability to store oxygenated blood during long dives.

In conclusion, the correct answer is B, as it does not provide support for the researchers' hypothesis that Antarctic seals store oxygenated blood in their spleens for long dives.