GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video

It is currently 09 Apr 2020, 16:33

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

Researchers conditioned a group of flies to associate a particular odo

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Find Similar Topics 
Senior Manager
Senior Manager
avatar
G
Joined: 04 Sep 2017
Posts: 291
Researchers conditioned a group of flies to associate a particular odo  [#permalink]

Show Tags

New post 22 Sep 2019, 19:51
2
1
25
00:00
A
B
C
D
E

Difficulty:

  75% (hard)

Question Stats:

60% (02:36) correct 40% (02:41) wrong based on 877 sessions

HideShow timer Statistics

Researchers conditioned a group of flies to associate a particular odor with a weak electric shock. Twenty-four and forty-eight hours later the researchers conducted tests on the flies, both individually and in groups, to determine whether the flies retained the conditioning. When tested individually, the flies were significantly less likely to avoid areas marked with the odor. The researchers hypothesized that in the presence of the odor, a fly that retains the conditioned association gives off an alarm signal that arouses the attention of any surrounding flies, retriggering the association in them and thereby causing them to avoid the odor.

The researchers' hypothesis requires which of the following assumptions?

A. The flies do not give off odors as alarm signals.
B. Flies that did not avoid the odor when tested individually were not merely following other flies' movements when tested in a group.
C. Flies that did not avoid the odor when tested individually were less likely than the other flies to avoid the odor when tested in a group.
D. Prior to their conditioning, the flies would likely have found the odor used in the experiment to be pleasant.
E. An electric shock was used during the flies' conditioning and during the later tests.


CR47931.01
Most Helpful Community Reply
Senior Manager
Senior Manager
avatar
G
Joined: 04 Sep 2017
Posts: 291
Re: Researchers conditioned a group of flies to associate a particular odo  [#permalink]

Show Tags

New post 29 Sep 2019, 01:42
5
1
gmatt1476 wrote:
Researchers conditioned a group of flies to associate a particular odor with a weak electric shock. Twenty-four and forty-eight hours later the researchers conducted tests on the flies, both individually and in groups, to determine whether the flies retained the conditioning. When tested individually, the flies were significantly less likely to avoid areas marked with the odor. The researchers hypothesized that in the presence of the odor, a fly that retains the conditioned association gives off an alarm signal that arouses the attention of any surrounding flies, retriggering the association in them and thereby causing them to avoid the odor.

The researchers' hypothesis requires which of the following assumptions?

A. The flies do not give off odors as alarm signals.
B. Flies that did not avoid the odor when tested individually were not merely following other flies' movements when tested in a group.
C. Flies that did not avoid the odor when tested individually were less likely than the other flies to avoid the odor when tested in a group.
D. Prior to their conditioning, the flies would likely have found the odor used in the experiment to be pleasant.
E. An electric shock was used during the flies' conditioning and during the later tests.


CR47931.01


Official Explanation

Argument Construction

This question asks us for an assumption required by the hypothesis.

The researchers noted that the flies that had been conditioned to associate a particular odor with an electric shock were much less likely to avoid the odor when they were tested individually than when they were tested as a part of a group.

Based on this fact, the researchers hypothesized that the flies that had retained the conditioning would give off an alarm when they detected the odor. This alarm would then retrigger the association among the other flies, leading them to avoid the odor.

We must consider whether there is some other fact that could explain why the flies were more likely to respond to the odor in a group than when they are alone. If there were, that alternative explanation would severely call into question the researchers' hypothesis. The hypothesis therefore requires that any such alternative explanation be false.

A. It is possible that the flies do in fact give off odors as an alarm signal. Because the nature of the flies' alarm signal is not specified by the hypothesis, this is entirely consistent with the hypothesis and would not undermine it. Therefore, the hypothesis does not require that flies do not give off odors as alarm signals.

B. Correct. Suppose that the flies that did not avoid the odor when tested individually were more likely to avoid the odor when in groups. This may be simply because these flies were following the movements of the flies that were triggered. That is, the signal did not cause the other flies' reactions. Instead, the movements of the triggered flies did. It follows that this possibility must be ruled out in order for the hypothesis to be plausible, and this answer choice does precisely that.

C. The hypothesis would actually be more plausible if this statement were false. That is, the hypothesis would be more plausible if the flies that did not avoid the odor when tested individually were just as likely, when they were tested in a group, to avoid the odor as the other flies in the group.

D. The hypothesis is perfectly compatible with the assumption that, prior to their conditioning, the flies were entirely indifferent to the odor.

E. The principle of association—that the shock is associated with the odor even when the shock itself is not present—actually requires that this statement be false.

The correct answer is B.
General Discussion
Senior Manager
Senior Manager
User avatar
G
Joined: 10 Sep 2013
Posts: 328
Location: India
Schools: Sloan '22, UVA Darden
GMAT 1: 720 Q50 V38
GPA: 4
CAT Tests
Re: Researchers conditioned a group of flies to associate a particular odo  [#permalink]

Show Tags

New post 23 Sep 2019, 07:18
B.IF theyy were merely following others, the conclusion stands invalid.
Manager
Manager
avatar
S
Joined: 05 Dec 2014
Posts: 227
Location: India
GMAT 1: 660 Q49 V31
GPA: 3.54
Re: Researchers conditioned a group of flies to associate a particular odo  [#permalink]

Show Tags

New post 27 Sep 2019, 06:04
ArtVandaley wrote:
B.IF theyy were merely following others, the conclusion stands invalid.


I marked B by POE( by applying negation), bt still did not get the clarity as why B and not A or C is the answer. Request you sincerley if you can help me how to tackle the argument.
Intern
Intern
avatar
B
Joined: 23 Jun 2019
Posts: 9
Re: Researchers conditioned a group of flies to associate a particular odo  [#permalink]

Show Tags

New post 27 Sep 2019, 15:48
How to eliminate B? Can't understand why C is correct here.
Director
Director
User avatar
P
Joined: 08 Aug 2017
Posts: 717
Re: Researchers conditioned a group of flies to associate a particular odo  [#permalink]

Show Tags

New post 27 Sep 2019, 18:05
1
Luckily I got it correct. But I appreciate detailed explanation for selecting B among other options.
Intern
Intern
avatar
B
Joined: 23 Nov 2018
Posts: 11
GMAT 1: 640 Q47 V31
GMAT 2: 690 Q48 V35
Researchers conditioned a group of flies to associate a particular odo  [#permalink]

Show Tags

New post 28 Sep 2019, 09:23
5
gvij2017

The reason why B is the correct answer is pretty straightforward:

" The researchers hypothesized that in the presence of the odor, a fly that retains the conditioned association gives off an alarm signal that arouses the attention of any surrounding flies, retriggering the association in them "

As is evident from the above text that the hypothesis was based on the ability of the flies to detect the alarm signals given by other members of their group.

By assumption negation option B says that the flies were merely following other flies and did not infact detect signals. This option throws the hypothesis out the window if negated , hence is the correct answer
Intern
Intern
avatar
Joined: 23 Sep 2019
Posts: 1
Re: Researchers conditioned a group of flies to associate a particular odo  [#permalink]

Show Tags

New post 29 Sep 2019, 01:00
How E could be eliminated ?..Anyone plz explain.

Posted from my mobile device
Intern
Intern
avatar
B
Joined: 30 Sep 2019
Posts: 30
Re: Researchers conditioned a group of flies to associate a particular odo  [#permalink]

Show Tags

New post 07 Nov 2019, 12:40
GMATNinja could you please put forth your opinions about this question.
I got C
GMAT Club Verbal Expert
User avatar
S
Joined: 20 Nov 2016
Posts: 263
Re: Researchers conditioned a group of flies to associate a particular odo  [#permalink]

Show Tags

New post 07 Nov 2019, 14:24
breatheanddoit wrote:
GMATNinja could you please put forth your opinions about this question.
I got C

Can you explain what led you to choice (C)? The more we know about your thought process, the easier it is for us to help (and the more likely that you'll get a reply!).
_________________
Intern
Intern
avatar
B
Joined: 30 Sep 2019
Posts: 30
Re: Researchers conditioned a group of flies to associate a particular odo  [#permalink]

Show Tags

New post 07 Nov 2019, 23:43
GMATNinjaTwo wrote:
breatheanddoit wrote:
GMATNinja could you please put forth your opinions about this question.
I got C

Can you explain what led you to choice (C)? The more we know about your thought process, the easier it is for us to help (and the more likely that you'll get a reply!).



Since in option c - Flies that did not avoid the odour when tested individually were less likely than the other flies to avoid the odour when tested in a group.
So if the flies that didn't avoid the odour individually didn't avoid it in groups too .
It would indicate that the conditional association and not any other reason is responsible for some flies to respond to the odour
Senior Manager
Senior Manager
avatar
P
Joined: 27 Aug 2014
Posts: 298
Location: Netherlands
Concentration: Finance, Strategy
Schools: LBS '22, ISB '21
GPA: 3.9
WE: Analyst (Energy and Utilities)
Re: Researchers conditioned a group of flies to associate a particular odo  [#permalink]

Show Tags

New post 10 Nov 2019, 12:02
1
Understanding the sentence:
Researchers basically trained a group of flies to connect with a particular smell with an electric shock. After some hours, researchers tested the flies both individually and in groups. This test was done to determine if the flies still retained the training.
Individual test result: Flies would not avoid the areas with smell
Theory of researchers: When smell is there, a fly that is trained sends a signal to the other flies like a warning and these flies would then avoid the smell.

A. The flies do not give off odors as alarm signals.
--> This answer is irrelevant on the assumption of the researchers

B. Flies that did not avoid the odor when tested individually were not merely following other flies' movements when tested in a group.
This is the right assumption that makes the hypothesis/theory stand. If the flies tested in the group are merely following the movements of the other flies, then the signal thing which researchers assume does not hold.
Therefore, this is the right assumption.


C. Flies that did not avoid the odor when tested individually were less likely than the other flies to avoid the odor when tested in a group.
This does not tell anything as the statement is trying to compare the flies that did not avoid individually vs other flies in the group that would avoid the smell.

D. Prior to their conditioning, the flies would likely have found the odor used in the experiment to be pleasant.
Irrelevant as the kind of smell is not discussed in the passage

E. An electric shock was used during the flies' conditioning and during the later tests.
Also not relevant for the hypothesis as the theory basically deals with the signal sent by induvial flies




Researchers conditioned a group of flies to associate a particular odor with a weak electric shock. Twenty-four and forty-eight hours later the researchers conducted tests on the flies, both individually and in groups, to determine whether the flies retained the conditioning. When tested individually, the flies were significantly less likely to avoid areas marked with the odor. The researchers hypothesized that in the presence of the odor, a fly that retains the conditioned association gives off an alarm signal that arouses the attention of any surrounding flies, retriggering the association in them and thereby causing them to avoid the odor.

The researchers' hypothesis requires which of the following assumptions?

A. The flies do not give off odors as alarm signals.
B. Flies that did not avoid the odor when tested individually were not merely following other flies' movements when tested in a group.
C. Flies that did not avoid the odor when tested individually were less likely than the other flies to avoid the odor when tested in a group.
D. Prior to their conditioning, the flies would likely have found the odor used in the experiment to be pleasant.
E. An electric shock was used during the flies' conditioning and during the later tests.
Manager
Manager
avatar
S
Joined: 20 Oct 2018
Posts: 224
GMAT 1: 690 Q49 V34
GMAT 2: 740 Q50 V40
Re: Researchers conditioned a group of flies to associate a particular odo  [#permalink]

Show Tags

New post 16 Nov 2019, 02:39
gmatt1476 wrote:
Researchers conditioned a group of flies to associate a particular odor with a weak electric shock. Twenty-four and forty-eight hours later the researchers conducted tests on the flies, both individually and in groups, to determine whether the flies retained the conditioning. When tested individually, the flies were significantly less likely to avoid areas marked with the odor. The researchers hypothesized that in the presence of the odor, a fly that retains the conditioned association gives off an alarm signal that arouses the attention of any surrounding flies, retriggering the association in them and thereby causing them to avoid the odor.

The researchers' hypothesis requires which of the following assumptions?


Passage explanation:
Let us consider there are 6 flies. Now researches trained the flies such that whenever they smell a particular odor (say smell of a nice pie), the flies would associate that smell with a shocking sensation and tend to avoid that area.

Now they conducted two types of tests:
1. Lets say they kept a freshly baked pie in an area. Now out of 6 flies, say 2 flies (A and B) went and sat on pie. They did not recall the shocking sensation on smelling the pie. A and B sat on pie in 7 out of 10 trials and rest sat on pie only in 2 out of 10 trials

2. Now they conducted a similar test with 6 flies. The two flies, A and B, sat on the pie only in 4 out of 10 trials.

Hypothesis: The other flies(other than A and B) sent an alarm signal when they smelled the pie. This alarm signal triggered a shock response in A and B, and hence A and B avoided sitting on the pie

Question type - Assumption
It could be a case, that the other flies did not send a signal. Instead in a group, there generally an alpha fly who the other flies obey. So consider a case, that the shock response was triggered in the alpha fly and it simply moved away from pie. Thus the other flies also followed the fly and moved away from the pie. This suggests that there was no alarm signal.

A. The flies do not give off odors as alarm signals.
The argument does not mention the form of alarm signal. It could be a wink, an odor, a sound anything. So this option does not affect the conclusion

B. Flies that did not avoid the odor when tested individually were not merely following other flies' movements when tested in a group.
Exactly what we thought. It the flies were merely imitating the alpha fly the alarm was never triggered, the shock response was never generated and the hypothesis falls apart Correct answer

C. Flies that did not avoid the odor when tested individually were less likely than the other flies to avoid the odor when tested in a group.
This suggests that the flies A and B, sat on pie less number of times than the other flies in the case when tested in the group than when tested in individually. Okay good. That is supporting the argument but it is not an assumption. The information does not shed any light on why they sat less number of times. Is it because they were merely following the leader or the shock sensation was triggered.

D. Prior to their conditioning, the flies would likely have found the odor used in the experiment to be pleasant.
This is irrelevant. We are trying to find if the odor triggers the sensation. The type of odor does not affect the argument

E. An electric shock was used during the flies' conditioning and during the later tests.
This means that we do not know if the results of the action were because of odor triggering the sensation or because of the physical shocks.

Please correct me if I have misunderstood anything!
Manager
Manager
avatar
B
Joined: 14 Nov 2018
Posts: 89
Location: United Arab Emirates
GMAT 1: 590 Q42 V30
GPA: 2.6
Re: Researchers conditioned a group of flies to associate a particular odo  [#permalink]

Show Tags

New post 16 Nov 2019, 04:41
I got C because I did not negate the question answer choice properly. Can someone confirm if this is the correct negation for B and C? Thanks in advance. Delete Bold and add in italics

B. Flies that did not avoid the odor when tested individually were not merely following other flies' movements when tested in a group.
C. Flies that did not avoid the odor when tested individually were less more likely than the other flies to avoid the odor when tested in a group.
Senior Manager
Senior Manager
avatar
P
Joined: 23 Nov 2016
Posts: 385
GMAT 1: 690 Q50 V33
GMAT ToolKit User Reviews Badge
Re: Researchers conditioned a group of flies to associate a particular odo  [#permalink]

Show Tags

New post 25 Feb 2020, 21:13
Conclusion states that The researchers hypothesized that in the presence of the odor, a fly that retains the conditioned association gives off an alarm signal that arouses the attention of any surrounding flies, retriggering the association in them and thereby causing them to avoid the odor.

Now if the flies were merely following the route of the other flies then the conclusion does not hold true.

Other options do not have any effect on the conclusion

Hence B
GMAT Club Bot
Re: Researchers conditioned a group of flies to associate a particular odo   [#permalink] 25 Feb 2020, 21:13
Display posts from previous: Sort by

Researchers conditioned a group of flies to associate a particular odo

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne