Studies of the Weddell seal in the laboratory have described the

Question

Studies of the Weddell seal in the laboratory have described the physiological mechanisms that allow the seal to cope with the extreme oxygen deprivation that occurs during its longest dives, which can extend 500 meters below the ocean’s surface and last for over 70 minutes. Recent field studies, however, suggest that during more typical dives in the wild, this seal’s physiological behavior is different.

In the laboratory, when the seal dives below the surface of the water and stops breathing, its heart beats more slowly, requiring less oxygen, and its arteries become constricted, ensuring that the seal’s blood remains concentrated near those organs most crucial to its ability to navigate underwater. The seal essentially shuts off the flow of blood to other organs, which either stop functioning until the seal surfaces or switch to an anaerobic (oxygen-independent) metabolism. The latter results in the production of large amounts of lactic acid which can adversely affect the pH of the seal’s blood, but since the anaerobic metabolism occurs only in those tissues which have been isolated from the seal’s blood supply, the lactic acid is released into the seal’s blood only after the seal surfaces, when the lungs, liver, and other organs quickly clear the acid from the seal’s bloodstream.

Recent field studies, however, reveal that on dives in the wild, the seal usually heads directly for its prey and returns to the surface in less than twenty minutes. The absence of high levels of lactic acid in the seal’s blood after such dives suggests that during them, the seal’s organs do not resort to the anaerobic metabolism observed in the laboratory, but are supplied with oxygen from the blood. The seal’s longer excursions underwater, during which it appears to be either exploring distant routes or evading a predator, do evoke the diving response seen in the laboratory. But why do the seal’s laboratory dives always evoke this response, regardless of their length or depth? Some biologists speculate that because in laboratory dives the seal is forcibly submerged, it does not know how long it will remain underwater and so prepares for the worst.   1 
 1. The passage provides information to support which of the following generalizations?

(A) Observations of animals’ physiological behavior in the wild are not reliable unless verified by laboratory studies.

(B) It is generally less difficult to observe the physiological behavior of an animal in the wild than in the laboratory.

(C) The level of lactic acid in an animal’s blood is likely to be higher when it is searching for prey than when it is evading predators.

(D) The level of lactic acid in an animal’s blood is likely to be lowest during those periods in which it experiences oxygen deprivation.

(E) The physiological behavior of animals in a laboratory setting is not always consistent with their physiological behavior in the wild.

2 
 2. It can be inferred from the passage that by describing the Weddell seal as preparing “for the worst” (line 41), biologists mean that it

(A) prepares to remain underwater for no longer than twenty minutes

(B) exhibits physiological behavior similar to that which characterizes dives in which it heads directly for its prey

(C) exhibits physiological behavior similar to that which characterizes its longest dives in the wild

(D) begins to exhibit predatory behavior

(E) clears the lactic acid from its blood before attempting to dive

3 
 3. The passage suggests that during laboratory dives, the pH of the Weddell seal’s blood is not adversely affected by the production of lactic acid because

(A) only those organs that are essential to the seal’s ability to navigate underwater revert to an anaerobic mechanism

(B) the seal typically reverts to an anaerobic metabolism only at the very end of the dive

(C) organs that revert to an anaerobic metabolism are temporarily isolated from the seal’s bloodstream

(D) oxygen continues to be supplied to organs that clear lactic acid from the seal’s bloodstream

(E) the seal remains submerged for only short periods of time

4 
 4. Which of the following best summarizes the main point of the passage?

(A) Recent field studies have indicated that descriptions of the physiological behavior of the Weddell seal during laboratory dives are not applicable to its most typical dives in the wild.

(B) The Weddell seal has developed a number of unique mechanisms that enable it to remain submerged at depths of up to 500 meters for up to 70 minutes.

(C) The results of recent field studies have made it necessary for biologists to revise previous perceptions of how the Weddell seal behaves physiologically during its longest dives in the wild.

(D) Biologists speculate that laboratory studies of the physiological behavior of seals during dives lasting more than twenty minutes would be more accurate if the seals were not forcibly submerged.

(E) How the Weddell seal responds to oxygen deprivation during its longest dives appears to depend on whether the seal is searching for prey or avoiding predators during such dives.

5 
 5. According to the author, which of the following is true of the laboratory studies mentioned in line 1?

(A) They fail to explain how the seal is able to tolerate the increased production of lactic acid by organs that revert to an anaerobic metabolism during its longest dives in the wild.

(B) They present an oversimplified account of mechanisms that the Weddell seal relies on during its longest dives in the wild.

(C) They provide evidence that undermines the view that the Weddell seal relies on an anaerobic metabolism during its most typical dives in the wild.

(D) They are based on the assumption that Weddell seals rarely spend more than twenty minutes underwater on a typical dive in the wild.

(E) They provide an accurate account of the physiological behavior of Weddell seals during those dives in the wild in which they are either evading predators or exploring distant routes.

6 
 6. The author cites which of the following as characteristic of the Weddell seal’s physiological behavior during dives observed in the laboratory?

I. A decrease in the rate at which the seal’s heart beats
II. A constriction of the seal’s arteries
III. A decrease in the levels of lactic acid in the seal’s blood
IV. A temporary halt in the functioning of certain organs

(A) I and III only
(B) II and IV only
(C) II and III only
(D) I, II, and IV only
(E) I, III, and IV only

7 
 7. The passage suggests that because Weddell seals are forcibly submerged during laboratory dives, they do which of the following?

(A) Exhibit the physiological responses that are characteristic of dives in the wild that last less than twenty minutes.
(B) Exhibit the physiological responses that are characteristic of the longer dives they undertake in the wild.
(C) Cope with oxygen deprivation less effectively than they do on typical dives in the wild.
(D) Produce smaller amounts of lactic acid than they do on typical dives in the wild.
(E) Navigate less effectively than they do on typical dives in the wild.

huongguyen · Accepted Answer

1. The passage provides information to support which of the following generalizations?
(A) Observations of animals’ physiological behavior in the wild are ~~not reliable~~ unless verified by laboratory studies. → wrong, the psg points out the difference btw "lab seal" & "wild seal", nowhere in the psg mentions "reliable"

(B) It is generally ~~less difficult~~ to observe the physiological behavior of an animal in the wild than in the laboratory. → Wrong

(C) The level of lactic acid in an animal’s blood is likely to be ~~higher~~ when it is searching for prey ~~than~~ when it is evading predators.

(D) The level of lactic acid in an animal’s blood is likely to be ~~lowest~~ during those periods in which it experiences oxygen deprivation.

(E) The physiological behavior of animals in a laboratory setting is not always consistent with their physiological behavior in the wild. → correct

2. It can be inferred from the passage that by describing the Weddell seal as preparing “for the worst” (line 41), biologists mean that it
Scope: “The seal’s longer excursions underwater, during which it appears to be either exploring distant routes or evading a predator, do evoke the diving response seen in the laboratory. But why do the seal’s laboratory dives always evoke this response, regardless of their length or depth? Some biologists speculate that because in laboratory dives the seal is forcibly submerged, it does not know how long it will remain underwater and so prepares for the worst.”

(A) prepares to remain underwater for ~~no longer than twenty minutes~~

(B) exhibits physiological behavior similar to that which characterizes dives in which it ~~heads directly for its prey~~

(C) exhibits physiological behavior similar to that which characterizes its longest dives in the wild

(D) begins to exhibit ~~predatory behavior~~

(E) clears the ~~lactic acid~~ from its blood before attempting to dive --> out of scope

3. The passage suggests that during laboratory dives, the pH of the Weddell seal’s blood is not adversely affected by the production of lactic acid because
Scope lines: “The seal essentially shuts off the flow of blood to other organs, which either stop functioning until the seal surfaces or switch to an anaerobic (oxygen-independent) metabolism. The latter results in the production of large amounts of lactic acid which can adversely affect the pH of the seal’s blood, but since the anaerobic metabolism occurs only in those tissues which have been isolated from the seal’s blood supply, the lactic acid is released into the seal’s blood only after the seal surfaces, when the lungs, liver, and other organs quickly clear the acid from the seal’s bloodstream.”

(A) only those organs that are essential to the seal’s ability to navigate underwater ~~revert~~ to an anaerobic mechanism

(B) the seal typically reverts to an anaerobic metabolism only ~~at the very end~~ of the dive

(C) organs that revert to an anaerobic metabolism are temporarily isolated from the seal’s bloodstream

(D) ~~oxygen continues to be supplied~~ to organs that clear lactic acid from the seal’s bloodstream

(E) the seal remains submerged for ~~only short periods of time~~

4. Which of the following best summarizes the main point of the passage?

(A) Recent field studies have indicated that descriptions of the physiological behavior of the Weddell seal during laboratory dives are not applicable to its most typical dives in the wild.

(B) The Weddell seal has developed a number of unique mechanisms that enable it to remain submerged at depths of up to ~~500 meters for up to 70 minutes~~. --> minor fact

(C) The results of recent field studies have made it necessary for biologists to ~~revise previous perceptions~~ of how the Weddell seal behaves physiologically during its longest dives in the wild.
→ last paragraph: “speculate”

(D) Biologists speculate that laboratory studies of the physiological behavior of seals during dives lasting more than twenty minutes would be more accurate if the seals were not forcibly submerged.
--> biologist speculate about the behavior of the seals, not the accuracy of the studies.

(E) How the Weddell seal responds to oxygen deprivation during its longest dives appears to depend on whether the seal is searching for ~~prey or avoiding predators~~ during such dives. → minor fact

5. According to the author, which of the following is true of the laboratory studies mentioned in line 1?
Scope line: “Studies of the Weddell seal in the laboratory have described the physiological mechanisms that allow the seal to cope with the extreme oxygen deprivation that occurs during its longest dives, which can extend 500 meters below the ocean’s surface and last for over 70 minutes”

(A) They ~~fail to explain~~ how the seal is able to tolerate the increased production of lactic acid by organs that revert to an anaerobic metabolism during its longest dives in the wild.

(B) They present an ~~oversimplified account~~ of mechanisms that the Weddell seal relies on during its longest dives in the wild.

(C) They provide evidence that ~~undermines the view~~ that the Weddell seal relies on an anaerobic metabolism during its most typical dives in the wild.

(D) They are based on the ~~assumption~~ that Weddell seals rarely spend more than twenty minutes underwater on a typical dive in the wild.

(E) They provide an accurate account of the physiological behavior of Weddell seals during those dives in the wild in which they are either evading predators or exploring distant routes.

6. The author cites which of the following as characteristic of the Weddell seal’s physiological behavior during dives observed in the laboratory?

I. A decrease in the rate at which the seal’s heart beats → Correct
II. A constriction of the seal’s arteries → correct
III. A decrease in the levels of lactic acid in the seal’s blood → wrong
“the latter results in the production of large amounts of lactic acid which can adversely affect the pH of the seal’s blood,”
IV. A temporary halt in the functioning of certain organs → correct

(A) I and III only
(B) II and IV only
(C) II and III only
(D) I, II, and IV only
(E) I, III, and IV only

7. The passage suggests that because Weddell seals are forcibly submerged during laboratory dives, they do which of the following?

(A) Exhibit the physiological responses that are characteristic of dives in the wild that ~~last less than twenty minutes.~~
(B) Exhibit the physiological responses that are characteristic of the longer dives they undertake in the wild.
(C) Cope with oxygen deprivation ~~less effectively~~ than they do on typical dives in the wild.
(D) Produce ~~smaller amounts of lactic acid~~ than they do on typical dives in the wild.
(E) Navigate ~~less effectively~~ than they do on typical dives in the wild.

------------------------------------------------
appreciate your +1 kudo

tarunanandani · Answer

5. According to the author, which of the following is true of the laboratory studies mentioned in line 1?

(A) They  fail to explain  how the seal is able to tolerate the increased production of lactic acid by organs that revert to an anaerobic metabolism during its longest dives in the wild. 
 Incorrect , detailed explanation is described in Para 2 about how seal is able to deal with the levels of lactic acid.

(B) They present an  oversimplified  account of mechanisms that the Weddell seal relies on during its longest dives in the wild.
 Incorrect , again a detailed description is given in Para 2 about the mechanism, so the studies do not only present a simplified explanation.

(C) They provide evidence that  undermines  the view that the Weddell seal relies on an anaerobic metabolism during its most typical dives in the wild.
 Incorrect , the studies provide support for an anaerobic metabolism.

(D) They are based on the  assumption  that Weddell seals rarely spend more than twenty minutes underwater on a typical dive in the wild.
 Incorrect , no such assumptions are mentioned in the passage while conducting the studies in the lab.

(E) They provide an  accurate account  of the physiological behavior of Weddell seals during those dives in the wild in which they are either  evading predators  or exploring  distant routes .
 Correct , as described in the Para 3, the studies conducted in the lab accurately explains the seal's behavior during longer dives.

pk123 · Answer

5. According to the author, which of the following is true of the laboratory studies mentioned in line 1?

(A) They fail to explain how the seal is able to tolerate the increased production of lactic acid by organs that revert to an anaerobic metabolism during its longest dives in the wild.

(B) They present an oversimplified account of mechanisms that the Weddell seal relies on during its longest dives in the wild.

(C) They provide evidence that undermines the view that the Weddell seal relies on an anaerobic metabolism during its most typical dives in the wild.

(D) They are based on the assumption that Weddell seals rarely spend more than twenty minutes underwater on a typical dive in the wild.

(E) They provide an accurate account of the physiological behavior of Weddell seals during those dives in the wild in which they are either evading predators or exploring distant routes.

--I was confused with option B and E and marked B.
1st paragraph talks about laboratory result but at the same time there were objections to the same. So it looked like its an oversimplified account of mechanisms that Weddell seal relies on longest dives in the world... while E is factually 100% correct but is it the reason 1st paragraph is being written?

pk123 · Answer

Tarun, I do agree Option E is 100% factual and is correct...but since question asks about para 1, should we be more focused towards overall scope...or specific to para1 with respect to entire passage scope....moreover oversimplified and detailed description are two different things....oversimplified means overly simplistic....completely opposite will be complex/complicated....so not sure this is the reason to omit option B...

@workout /@broall/  GMATNinja  need you expert comments here

Diwakar003 · Answer

5. According to the author, which of the following is true of the laboratory studies mentioned in   line 1?

Hey pk123, I don't think the question asks only about Para 1, the question asks about the studies mentioned in line 1. The information about this study can be scattered anywhere in the RC. So the scope is definitely broader here.

Cheers!

redskull1 · Answer

6:01 for the 7 questions.All correct.Is not taking notes actually helpfull?

Read for the overall structure since this is a longish passage.

Q) 5

B & E appear to be the major contenders

B - obviously incorrect because nothing is mentioned in the passage about the process being simple.It is just a description of the process.Why did it occur to anybody(32%at the time of writing) that the process is a simplified process???would love to hear some views.

E - This is more like it.The seals in laboratory = seals who spend more time without knowing when they will come out = similar to seals exhibiting certain behavior in the wild.

tarunanandani · Answer

Hello pk123, as Diwakar003 said the question asks about the studies mentioned in line 1, i.e., the studies in the lab and not the studies in the wild. So, the scope of the question is not limited to para 1.

Hope this helps!

hiranmay · Answer

1. The passage provides information to support which of the following generalizations?

(A) Observations of animals’ physiological behavior in the wild are not reliable unless verified by laboratory studies. --> no such dependency has been described in the passage, lab experiments are done to come out w/ the results in lab, but not because the results are unreliable in wild.

(B) It is generally less difficult to observe the physiological behavior of an animal in the wild than in the laboratory. --> no such comparison has been done. similar to A

(C) The level of lactic acid in an animal’s blood is likely to be higher when it is searching for prey than when it is evading predators. --> no such comparison has been made in the passage, In para-2, it says anaerobic results in lactic acid, never shows any comparison

(D) The level of lactic acid in an animal’s blood is likely to be lowest during those periods in which it experiences oxygen deprivation. --> same as C

(E) The physiological behavior of animals in a laboratory setting is not always consistent with their physiological behavior in the wild. -->  correct : it has been shown in line-2, para-3 that the lactic acid level after the dive in the wild can't be always described by the experiment results in the labratory

Navisha · Answer

main points of the passage , anyone ?

PrachiMaloo · Answer

Can anyone explain questions 4 and 7?

tkorzhan1995 · Answer

GMATNinja , can you please explain why B is not correct for q3 ?
 I established the following relationship among chain of events:
anaerobic metabolism--> supply of lactic acid--> lactic acid affects ph. 
It is noted in the second paragraph that lactic acid is released when seal surfaces (would it be the end of dive when seal surfaces?). As a result of production of lactic acid when seal surfaces (the end of the dive), the ph will be impacted by the production of lactic acid. 
Since lactic acid is produced when seal surfaces, the ph will be impacted when seal surfaces (the end of the dive).

GMATNinja · Answer

Question 3 
 
In the second paragraph, the author tells us that there is a difference between when the lactic acid is  produced  by anaerobic metabolism, and when it is  released  into the blood stream.

Lactic acid is  produced  "when the seal dives below the surface of the water and stops breathing." At this time, the seal shuts off the flow of blood to certain organs, and these organs either stop functioning or switch to anaerobic metabolism.

Later, when the seal resurfaces, it opens up its blood flow again and  releases  the built-up lactic acid into its blood.

So, it's not quite right to say that the seal reverts to an anaerobic metabolism only at the very end of the dive, as stated in (B) -- the seal actually starts anaerobic metabolism at the  beginning  of the dive.

Eliminate (B).

Here's (C):
 
This is exactly how the seal keeps its blood pH on track! It isolates certain organs until it resurfaces, at which point it can get rid of the lactic acid that has built up in those organs.

(C) is the correct answer to question 3.

I hope that helps!

tkorzhan1995 · Answer

GMATNinja , thank you for explaining q3. It was helpful. 
 Can you please clarify for q5 how we can infer from the passage that studies provide accurate account? I cannot determine from the passage about author's attitude for studies conducted in the wild.

sea0920 · Answer

Question 5 asks "According to the author, which of the following is true of  the laboratory studies  mentioned in line 1?"

The answer E describes the same mechanism but the one that happens  in the wild .

Doesn't the author want to point out the fact that the conclusion in the lab study was oversimplied in the sense that it doesn't fully cover the short-range and long-range strategies of the Weddell seal? Why would the author wanna say something like, "According to the author, they provide an accurate account of ~"

I think the answer B is more closer but the rotten part of the answer B is that it is referring to "its longest dives in the wild".

I think neither answer B and E are satisfactory answers.

kirti140699 · Answer

5. According to the author, which of the following is true of the laboratory studies mentioned in line 1?

(A) They fail to explain how the seal is able to tolerate the increased production of lactic acid by organs that revert to an anaerobic metabolism during its longest dives in the wild.

(B) They present an oversimplified account of mechanisms that the Weddell seal relies on during its longest dives in the wild.

(C) They provide evidence that undermines the view that the Weddell seal relies on an anaerobic metabolism during its most typical dives in the wild.

(D) They are based on the assumption that Weddell seals rarely spend more than twenty minutes underwater on a typical dive in the wild.

(E) They provide an accurate account of the physiological behavior of Weddell seals during those dives in the wild in which they are either evading predators or exploring distant routes.

Solution - I was confused between B and E.

I feel B is more closer because-
In the first line of the passage, the author is  only introducing the context of Weddell seals study which can be inferred as oversimplified.

whereas in option E- it is saying  accurate account of physiological behaviour , which seems a very  extreme option . Nowhere in the first line, it is mentioned that the studies conducted were accurate.

makshay62 · Answer

Hi  GMATNinja  / Other faculty, 
Could you please help me understand a bit more as why (A) is a better choice than (D) in Question 4?

4. Which of the following best summarizes the main point of the passage?

(A) Recent field studies have indicated that descriptions of the physiological behavior of the Weddell seal during laboratory dives are not applicable to its most typical dives in the wild.

(B) The Weddell seal has developed a number of unique mechanisms that enable it to remain submerged at depths of up to 500 meters for up to 70 minutes.

(C) The results of recent field studies have made it necessary for biologists to revise previous perceptions of how the Weddell seal behaves physiologically during its longest dives in the wild.

(D) Biologists speculate that laboratory studies of the physiological behavior of seals during dives lasting more than twenty minutes would be more accurate if the seals were not forcibly submerged.

(E) How the Weddell seal responds to oxygen deprivation during its longest dives appears to depend on whether the seal is searching for prey or avoiding predators during such dives.

GMATNinja · Answer

Question 4 
 
The biologists do indeed speculate that the forcibly submersion might explain the difference between observations in the lab and observations in the wild.

But that's not quite what (D) says. (D) says that the lab results would be MORE accurate if the seals were not forcibly submerge. This certainly seems plausible, but the biologists in the passage never speculate on what the accuracy of the lab studies would be if the seals were  not  forcibly submerged.

In other words, just because forcible submersion might cause an issue with the study does not necessarily mean that the study would be more accurate without forcible submersion. Perhaps removing forcible submersion would lead to some other, different issues that affect the accuracy even more than the forcible submersion did.

It's certainly possible that the biologists would agree with (D), but (D) doesn't actually reflect what's said about the biologists in the passage.

Studies of the Weddell seal in the laboratory have described the

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GMAT Reading Comprehension (RC) Questions

Studies of the Weddell seal in the laboratory have described the

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