Although scientists observe that an organism’s behavior falls into

Question

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Passage # 174 Date: 26-Jun-2020
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2-2 SECTION B 17-20

Although scientists observe that an organism’s behavior falls into rhythmic patterns, they disagree about how these patterns are affected when the organism is transported to a new environment. One experimenter, Brown, brought oysters from Connecticut waters to Illinois waters. She noted that the oysters initially opened their shells widest when it was high tide in Connecticut, but that after fourteen days their rhythms had adapted to the tide schedule in Illinois. Although she could not posit an unequivocal causal relationship between behavior and environmental change, Brown concluded that a change in tide schedule is one of several possible exogenous influences (those outside the organism) on the oysters’ rhythms. Another experimenter, Hamner, however, discovered that hamsters from California maintain their original rhythms even at the South Pole. He concluded that endogenous influences (those inside the organism) seem to affect an organism’s rhythmic behavior.  
 1 
 1. ​​All of the following could be considered examples of exogenous influences on an organism EXCEPT the influence of the

(A) level of a hormone on a field mouse’s readiness for mating
(B) temperature of a region on a bear’s hibernation
(C) salt level of a river on a fish’s migration
(D) humidity of an area on a cat’s shedding of its fur
(E) proximity of an owl on a lizard’s searching for food

2 
 ​2. Which of the following statements best describes the conclusion drawn by Brown (lines 14-17)

(A) A change in tide schedule is the primary influence on an oyster’s rhythms.
(B) A change in tide schedule may be an important exogenous influence on an oyster’s rhythms.
(C) Exogenous influences, such as a change in tide schedule, seldom affect an oyster’s rhythms.
(D) Endogenous influences have no effect on an oyster’s rhythms.
(E) Endogenous influences are the only influences on an oyster’s rhythms.

3 
 3. ​​​​The passage suggests that Brown’s study was similar to Hamner’s in which of the following ways?

I.​Both experimenters discovered that a new environment had a significant effect on an organism’s behavior rhythms.
II.​Both experimenters observed an organism’s behavioral rhythms after the organism had been transported to a new environment.
III.​Both experimenters knew an organism’s rhythmic patterns in its original environment.
(A) I only
(B) II only
(C) I and II only
(D) II and III only
(E) I, II, and III

4 
 4. ​​​​​​​​Which of the following, if true, would most weaken Brown’s conclusion?

(A) The oyster gradually closed their shells after high tide in Illinois had passed.
(B) The oysters’ behavioral rhythms maintained their adaptation to the tide schedule in Illinois throughout thirty days of observation.
(C) Sixteen days after they were moved to Illinois, the oysters opened their shells widest when it was high tide in Connecticut.
(D) A scientist who brought Maryland oysters to Maine found that the oysters opened their shells widest when it was high tide in Maine.
(E) In an experiment similar to Brown’s, a scientist was able to establish a clear causal relationship between environmental change and behavioral rhythms.

Geet91 · Answer

Hi, please someone post the explanation as well for the correct answers.

Codebug4it · Answer

Hi  Geet91 ,

I hope these explanations help.

1. ​​All of the following could be considered examples of exogenous influences on an organism EXCEPT the influence of the

=> We need to find an example which is Endogenous, not exogenous

(A) level of a hormone on a field mouse’s readiness for mating
 => Hormone is from inside the organism, hence it is  endogenous , not exogenous

(B) temperature of a region on a bear’s hibernation
 => Temperature of a region is an environmental element, not part of an organism, hence it is exogenous

(C) salt level of a river on a fish’s migration
 => salt level of a river is an environmental element, not part of an organism, hence it is exogenous

(D) humidity of an area on a cat’s shedding of its fur
 => humidity of an area is an environmental element, not part of an organism, hence it is exogenous

(E) proximity of an owl on a lizard’s searching for food
 => proximity of an owl is an environmental element, not part of an organism, hence it is exogenous

Answer:   Option A

Codebug4it · Answer

2. Which of the following statements best describes the conclusion drawn by Brown (lines 14-17)

=> "Brown concluded that a change in tide schedule is  one of several possible  exogenous influences (those outside the organism) on the oysters’ rhythms"

(A) A change in tide schedule is the primary influence on an oyster’s rhythms.
 => The passage says it is  "one of the several possible"  influences, but not the primary or most important influence

(B) A change in tide schedule may be an important exogenous influence on an oyster’s rhythms.
 => CORRECT. This option suggests it is an exogenous influence and chances are that it is important. This resembles with Brown's conclusion.

(C) Exogenous influences, such as a change in tide schedule, seldom affect an oyster’s rhythms.
 => There is no info on how seldom/often the change in tide affected rhythms. It just says it is possible.

(D) Endogenous influences have no effect on an oyster’s rhythms.
 => Brown didn't make any comment on Endogenous influences.

(E) Endogenous influences are the only influences on an oyster’s rhythms.
 => Brown didn't make any comment on Endogenous influences.

Answer:   Option B

-------------------------------------------------------------------------------------------------------------------------------------------------------------
3. ​​​​The passage suggests that Brown’s study was similar to Hamner’s in which of the following ways?

I.​Both experimenters discovered that a new environment had a significant effect on an organism’s behavior rhythms.
 => No, both study's discovered opposite results.
=> Brown's study -> Exogenous or changes outside of organisms influences rhythms
=> Hamner’s study -> Endogenous or changes inside of organisms influences rhythms

II.​Both experimenters observed an organism’s behavioral rhythms after the organism had been transported to a new environment.
 => Yes true. Both the study's transported the organism to a new environment for observation, which are  Brown's study - "Connecticut waters to Illinois waters" and Hamner’s study - "California to the South Pole"

III.​Both experimenters knew an organism’s rhythmic patterns in its original environment.
 => Yes true. Both the study's compared the organism's rhythmic patterns from original environment to new environment, which suggests that they knew those patterns.

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

=>So the correct answer should be II and III

Answer:  Option D

Codebug4it · Answer

4. ​​​​​​​​Which of the following, if true, would most weaken Brown’s conclusion?

=> We have to weaken this conclusion by Brown ->  "She noted that the oysters initially opened their shells widest when it was high tide in Connecticut, but that after fourteen days their rhythms had adapted to the tide schedule in Illinois"

(A) The oyster gradually closed their shells after high tide in Illinois had passed.
 => This option supports Brown's claims that Oyster adapted to Illinois's environment.

(B) The oysters’ behavioral rhythms maintained their adaptation to the tide schedule in Illinois throughout thirty days of observation.
 => This option supports Brown's claims that Oyster adapted to Illinois's environment and maintained for 30 days.

(C) Sixteen days after they were moved to Illinois, the oysters opened their shells widest when it was high tide in Connecticut.
 => This option weakens Brown's claims because it says the oysters opened their shells widest as they do in the original environment, Connecticut, even when they were in Illinois after 16 days.

(D) A scientist who brought Maryland oysters to Maine found that the oysters opened their shells widest when it was high tide in Maine.
 => This option supports Brown's claims that Oysters adapted to the new environment.

(E) In an experiment similar to Brown’s, a scientist was able to establish a clear causal relationship between environmental change and behavioral rhythms.
 => This option supports Brown's claims that Oyster that the Exogenous influences Organism's rhythms. Hence supporting Brown's study.

Answer:   Option C

deep31993 · Answer

In question 4 answer choice (c) meaning is quite confusing to me. It implies that Sixteen days after they were moved to Illinois, oyesters moved to Connecticut, and there the action happened (in the original city).

Sajjad1994 · Answer

Please read this earlier posted explanation of question #4, it might help you. https://gmatclub.com/forum/although-sci ... l#p2532477 Thanks

VerbalBot · Answer

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Although scientists observe that an organism’s behavior falls into

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