Under laboratory conditions, fruit flies can learn to respond

Question

Under laboratory conditions, fruit flies can learn to respond to odors that elicit no response from them in nature. Mutant fruit flies that cannot produce a certain enzyme are, however, incapable of such learning.  These mutant flies respond to other odors just as ordinary fruit flies do.  Thus it is unlikely that the enzyme's absence impairs the fruit flies' perception of odors, since presumably  fruit flies would not have an enzyme that was needed only for the perception of odors that fruit flies do not respond to in nature.  Given that many researchers believe that this enzyme is somehow involved in the process of forming memories, what the enzyme's absence probably impairs is the fruit flies' ability to learn.

In the argument given, the two  boldfaced  portions play which of the following roles?

A) The first is an explanatory hypothesis provisionally put forward in the argument; the second provides evidence in support of that hypothesis.
B) The first is evidence that has been used to support a hypothesis that the argument challenges; the second states an assumption explicitly made in challenging that hypothesis.
C) The first is evidence that has been used to support a hypothesis that the argument challenges; the second is a modified version of that hypothesis that is adopted in the argument.
D) The first is evidence used in ruling out a potential explanation that the argument rejects; the second presents an explicit assumption used in arguing against that explanation.
E) The first is evidence used in ruling out a potential explanation that the argument rejects; the second is the explanatory hypothesis that the argument as a whole seeks to support.

gmatophobia · Accepted Answer

This is a tricky one and a lot is going on in this passage. Let's try to break down the passage.
  Under laboratory conditions, fruit flies can learn to respond to odors that elicit no response from them in nature.     → A fact is presented, hence, this statement is a premise of the argument. 
  Mutant fruit flies that cannot produce a certain enzyme are, however, incapable of such learning.   → A fact is presented, hence, this statement is a premise of the argument. 
  These mutant flies respond to other odors just as ordinary fruit flies do.   → A fact is presented, hence, this statement is a premise of the argument. 
  Thus it is unlikely that the enzyme's absence impairs the fruit flies' perception of odors   → The author concludes that "  it is unlikely that the enzyme's absence impairs the fruit flies' perception of odors   ". This statement is a conclusion. We don't know if this is an intermediatory conclusion or the main conclusion of the argument. So let's keep reading. 
  since presumably  fruit flies would not have an enzyme that was needed only for the perception of odors that fruit flies do not respond to in nature.    → Since is a premise marker. The statement provides some facts/reasons to support the conclusion. The word "presumably" indicates that the author is assuming the details. 
  Given that many researchers believe that this enzyme is somehow involved in the process of forming memories,   → The author provides evidence to support his claim. 
  what the enzyme's absence probably impairs is the fruit flies' ability to learn   → This part is again a conclusion and is the views of the author. 
Out of the two conclusions above "  Thus it is unlikely that the enzyme's absence impairs the fruit flies' perception of odors"   is the main conclusion of the argument. 
   Answer Choice Elimination   
 A)   The first is an explanatory hypothesis provisionally put forward in the argument ; the second provides evidence in support of that hypothesis.
The first part of this option is incorrect. The first bold fact doesn't explain anything but is merely a fact presented by the author. Hence, eliminate A. 
 B)   The first is evidence that has been used to support a hypothesis that the argument challenges ;  the second states an assumption explicitly made in challenging that hypothesis. 
The first boldface, "  These mutant flies respond to other odors just as ordinary fruit flies do  ", does serve as evidence to support a hypothesis, " it is unlikely that the enzyme's absence impairs the fruit flies' perception of odors " that the argument challenges. This is correct because the author does share his viewpoints in the second conclusion. He states " the enzyme's absence probably impairs the fruit flies' ability to learn ". So he believes that the absence of the enzymes doesn't impair the files' perception of odors but impairs its perception of learning.
The second part of the option is incorrect. The second boldface doesn't challenge the hypothesis but supports the hypothesis of the author. 
 C)   The first is evidence that has been used to support a hypothesis that the argument challenges ;  the second is a modified version of that hypothesis that is adopted in the argument .
The first boldface, "  These mutant flies respond to other odors just as ordinary fruit flies do  ", does serve as evidence to support a hypothesis, " it is unlikely that the enzyme's absence impairs the fruit flies' perception of odors " that the argument challenges. This is correct because the author does share his viewpoints in the second conclusion. He states " the enzyme's absence probably impairs the fruit flies' ability to learn ". So he believes that the absence of the enzymes doesn't impair the files' perception of odors but impairs its perception of learning.
The second bold face is not a modified version of the hypothesis but an assumption that's used to support the hypothesis. Hence, this option is incorrect. 
 D)   The first is evidence used in ruling out a potential explanation that the argument rejects ;  the second presents an explicit assumption used in arguing against that explanation .
The first part of the boldface is correct. The first boldface, "  These mutant flies respond to other odors just as ordinary fruit flies do  ", is used to rule out a potential explanation, "  that the enzyme's absence impairs the fruit flies' perception of odors  ", and the argument also rejects this explanation. 
The second boldface is also correct. It presents an assumption that the author has made while concluding. The author assumes that  fruit flies would not have an enzyme that was needed only for the perception of odors that fruit flies do not respond to in nature.  Also, the author challenges the explanation "  that the enzyme's absence impairs the fruit flies' perception of odors  ". Hence, both parts are correct. Let's keep. 
 E)   The first is evidence used in ruling out a potential explanation that the argument rejects ;  the second is the explanatory hypothesis that the argument as a whole seeks to support .
The first part of the boldface is correct. The first boldface, "  These mutant flies respond to other odors just as ordinary fruit flies do  ", is used to rule out a potential explanation, "  that the enzyme's absence impairs the fruit flies' perception of odors  ", and the argument also rejects this explanation. 
The second part of this option is incorrect. The second boldface is an assumption that's made while concluding. It's not doesn't explain anything. We can eliminate E. 
  Option D

Gemmie · Answer

The argument is trying to show that the enzyme is involved in learning, not perception.

These mutant flies respond to other odors just as ordinary fruit flies do .  Thus  it is unlikely that the enzyme's absence impairs the fruit flies' perception of odors,  since  presumably  fruit flies would not have an enzyme that was needed only for the perception of odors that fruit flies do not respond to in nature.

Both bold parts support the central argument that the enzyme is not involved in perception.

1. The first bold part  
- is an evidence => rule out A
- supports the argument => rule out B and C

D and E identify the same about the first bold part.

The first is evidence used in ruling out a potential explanation that the argument rejects

==> What is the mentioned explanation: 
+  the explanation  is for why  Under laboratory conditions, fruit flies can learn to respond to odors that elicit no response from them in nature. Mutant fruit flies that cannot produce a certain enzyme are, however, incapable of such learning  
 + the explanation says  that  enzyme's absence impairs the fruit flies' perception of odors

==> The argument rejects this explanation and says that the enzyme interfere with the learning ability

2. The second bold part

E suggests the argument supports the hypothesis mentioned in second bold part. However, it is the 2nd is rather an assumption based on which the argument (i.e. arguing against the explanation) is made, which is D

siddd30 · Answer

Hey,

I disagree with the claim wrt the first portion of option b and c, the first is evidence which is used to  challenge (and not support)  the hypothesis that the argument challenges, IMO.

Hypothesis that the argument challenges- "Enzyme's absence impairs the fruit flies' perception of odors"; so the fact that they can respond to other odors, just as ordinary fruit flies do- suggests that it isnt supporting a hypothesis that the argument challenges

Raman109 · Answer

Under laboratory conditions, fruit flies can learn to respond to odors that elicit no response from them in nature. - Background info. Fruit Flies (FF) can learn to respond to some odors that FF doesn't typically respond to in nature.

Mutant fruit flies that cannot produce a certain enzyme are, however, incapable of such learning. - Highlights an exception - MFF that can't produce enzyme X and is incapable of learning. Are these correlated? Is enzyme the reason for the lack of learning? We don't know.

These mutant flies respond to other odors just as ordinary fruit flies do . - Another complexity: the MFF responds to other odors. For example, dog type B doesn't respond to the car horns and has different genes than dog A. But that dog B responds to other sounds such as home ring, etc. Its going towards that possibly both are not related in terms of one causing the other.

Thus it is unlikely that the enzyme's absence impairs the fruit flies' perception of odors, since presumably  fruit flies would not have an enzyme that was needed only for the perception of odors that fruit flies do not respond to in nature.  - exactly. The enzyme can't be the reason/cause of lack of perception or response.

Given that many researchers believe that this enzyme is somehow involved in the process of forming memories, what the enzyme's absence probably impairs is the fruit flies' ability to learn. - opposite to the earlier statement, it means that the enzyme's absence is responsible in some form. How? Without this enzyme, they may still sense it but cant learn as this enzyme is responsible for forming memory.

In the argument given, the two boldfaced portions play which of the following roles?

A) The first is an explanatory hypothesis provisionally put forward in the argument (No, it just states another complexity/fact); the second provides evidence in support of that hypothesis (The 2nd BF is not in support of BF1. The 2nd is an assumption supporting the intermediate conclusion).

B) The first is evidence that has been used to support a hypothesis that the argument challenges (ok); the second states an assumption explicitly made in challenging that hypothesis. (No. It supports the hypothesis that "it is unlikely that the enzyme's absence impairs the fruit flies' perception of odors."

C) The first is evidence that has been used to support a hypothesis that the argument challenges (ok); the second is a modified version of that hypothesis that is adopted in the argument. - No. What is adopted in the argument is that enzymes are somehow responsible - not in perception but in learning.

D) The first is evidence (okay) used in ruling out a potential explanation (what explanation—that the enzyme is required for perception—the idea that the enzyme is important) that the argument rejects (the argument concludes that yes, the enzyme is not required for perception but is required for learning); the second presents an explicit assumption (ok) used in arguing against that explanation(yes the explanation that the enzyme is required for perception—the idea that the enzyme is important ).

E) The first is evidence used in ruling out a potential explanation that the argument rejects (ok); the second is the explanatory hypothesis that the argument as a whole seeks to support. (No, the conclusion doesn't support this)

Goldenfuture · Answer

Under laboratory conditions, fruit flies can learn to respond to odors that elicit no response from them in nature. Mutant fruit flies that cannot produce a certain enzyme are, however, incapable of such learning. 
BF1 – observation/ premise/ evidence These mutant flies respond to other odors just as ordinary fruit flies do. 
Conclusion: Thus it is unlikely that the enzyme's absence impairs the fruit flies' perception of odors,

since presumably fruit flies would not have an enzyme that was needed only for the perception of odors that fruit flies do not respond to in nature. – Explanation/ analysis thinking/ IC

Given that many researchers believe that this enzyme is somehow involved in the process of forming memories, what the enzyme's absence probably impairs is the fruit flies' ability to learn – Main conclusion.

In the argument given, the two boldfaced portions play which of the following roles?

A) The first is an explanatory hypothesis provisionally put forward in the argument; the second provides evidence in support of that hypothesis. – First not hypothesis- eliminate

B)  The first is evidence that has been used to support a hypothesis that the argument challenges;  the second states an assumption explicitly made in challenging that hypothesis. Point of failure highlighted

C)  The first is evidence that has been used to support a hypothesis that the argument challenges;  the second is a modified version of that hypothesis that is adopted in the argument. Point of failure highlighted

D) The first is evidence used in ruling out a potential explanation that the argument rejects; the second presents an explicit assumption used in arguing against that explanation - Keep
.
E) The first is evidence used in ruling out a potential explanation that the argument rejects; the second is the explanatory hypothesis that the argument as a whole seeks to support – Conclusion is built on BF2 not support it

Under laboratory conditions, fruit flies can learn to respond

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Under laboratory conditions, fruit flies can learn to respond