It is widely believed that lancelets—small, primitive sea animals—do

Question

It is widely believed that lancelets—small, primitive sea animals—do not have hearts. Each lancelet has a contracting vessel, but this vessel is considered an artery rather than a heart. However, this vessel is indeed a heart. After all, it strongly resembles the structure of the heart of certain other sea animals. Moreover, the muscular contractions in the lancelet’s vessel closely resemble the muscular contractions of other animals’ hearts.

The argument’s conclusion follows logically if which one of the following is assumed?

(A) Only animals that have contracting vessels have hearts.
(B) Some primitive animals other than lancelets have what is widely held to be a heart.
(C) A vessel whose structure and actions closely resemble those of other animal hearts is a heart.
(D) For a vessel in an animal to be properly considered a heart, that vessel must undergo muscular contractions.
(E) No animal that has a heart lacks an artery.

Bunuel · Accepted Answer

EXPLANATION FROM Fox LSAT

The conclusion here is, “The vessel is indeed a heart.” The evidence for this conclusion is in the last two sentences: “It strongly resembles the structure of the heart of certain other sea mammals,” and, “The contractions closely resemble the muscular contractions of other animals’ hearts.”

The question asks us to find an answer choice that would make the conclusion of the argument “follow logically” from the premises of the argument. This means we need to  prove  the conclusion of the argument using the facts we were given, plus one other fact (the correct answer).

After some preparation for the LSAT, I think it is possible for this type of question to become extremely easy. All we have to do here is bridge the gap between the facts and the conclusion. I think the best answer would be, “Anything that resembles another creature’s heart is itself a heart.” Let’s see if that’s somewhere in the answer choices.

A) Not what we’re looking for.

B) Not what we’re looking for.

C) Exactly what we were looking for. This must be it.

D) This one has the right words, but it says that contractions are  necessary  in order for something to be a heart, rather than  sufficient  to prove that something is a heart. This answer choice could therefore only ever be used to prove that something is not a heart (because if you lack a necessary condition for hearthood, then you are not a heart). C was better.

E) Not what we were looking for, and C was exactly what we were looking for.

So C has to be our answer.

Shikhar22 · Answer

C. Correct. Tackles both the assumptions about contractions and resemblance in one go.

D is a trap answer. It only deals with one of the premises.

Posted from my mobile device

shwetank07 · Answer

It is widely believed that lancelets—small, primitive sea animals—do not have hearts. Each lancelet has a contracting vessel, but this vessel is considered an artery rather than a heart. However, this vessel is indeed a heart. After all, it strongly resembles the structure of the heart of certain other sea animals. Moreover, the muscular contractions in the lancelet’s vessel closely resemble the muscular contractions of other animals’ hearts.

The argument’s conclusion follows logically if which one of the following is assumed?

(A) Only animals that have contracting vessels have hearts. : EXTREME ANS
(B) Some primitive animals other than lancelets have what is widely held to be a heart. : EXTERNAL FACTORS
(C)  A vessel whose structure and actions closely resemble those of other animal hearts is a heart : BINGO (STRUCTURE AND ACTIONS BOTH FACTORS CONSIDERED , CORRECT ) 
(D) For a vessel in an animal to be properly considered a heart, that vessel must undergo muscular contractions : TRAP ' SHELL GAME ANSWER
(E) No animal that has a heart lacks an artery : VAGUE , IRRELEVANT

minalgambhir · Answer

CONCLUSION - The vessel mentioned is a heart

PRETHINKING -

IN WHAT SCENARIO the vessel is not heart

GIVEN -

1) Lancet is believed not to have heart
2) Vessel is an artery
3) The vessel resembles the heart of other sea animals
4) Muscular contractions in the vessel are similar to other sea animals' heart

FALSIFICATION QUESTION - Resemblance of the vessel with the other animals' heart doesn't conclude that the vessel is a heart

ASSUMPTION - Resemblance of the vessel with other sea animals' heart signifies that the vessel is a heart

ANSWER CHOICE ANALYSIS -

A) Animals with vessels are not concerned with the argument. This is not the statement which must be true for the conclusion to be true
B) Same as A
C) CORRECT - Inline with our assumption
D) TRAP - Here all animals are talked about however in argument we talk about only sea animals
E) Same as D

saurabhking · Answer

how this assumption is maded????

TheGraceful · Answer

Although I got it correct, I realized my mistake and here is my analysis.

Premise-1:   It is widely believed that lancelets—small, primitive sea animals—do not have hearts. Each lancelet has a contracting vessel, but this vessel is considered an artery rather than a heart. 
  Conclusion:    However,  this  (lancelets's) vessel is indeed a heart. 
  Premise-2  : After all, it strongly resembles the structure of the heart of certain other sea animals. 
  Premise-3:   Moreover, the muscular contractions in the lancelet’s vessel closely resemble the muscular contractions of other animals’ hearts.

The argument’s conclusion follows logically if which one of the following is  assumed ?

(A) Only animals that have contracting vessels have hearts.
 ==> Conclusion is about lancelet's hearts. Moreover, its using extreme language (ONLY animals).   Eliminate this option.

(B) Some primitive animals other than lancelets have what is widely held to be a heart.
 ==> Conclusion is about lancelet's hearts. About a primitive  sea  animals.   Eliminate this option.

(C)  A vessel   whose structure and actions closely resemble those of other animal hearts   is a heart. 
 ==>Ummm doesn't seem correct in first glance. But is speaking about vessel (of primitive sea animal) which is part of conclusion. It also speaks about vessel being actually a heart.(mentioned in conclusion). So no reason to eliminate this.   Let's keep it.

(D) For a vessel in an animal to be properly considered a heart, that vessel must undergo muscular contractions.
 ==> Conclusion is about lancelet's hearts.   Eliminate this option.

(E) No animal that has a heart lacks an artery. 
 ==> Conclusion is about lancelet's hearts. About a primitive  sea  animals.Moreover, its using extreme language (No animal).   Eliminate this option.

Since we are left with only  one option  - option C - that's our correct answer  (  No matter how much we like or understand it  ).

VerbalBot · Answer

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It is widely believed that lancelets—small, primitive sea animals—do

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It is widely believed that lancelets—small, primitive sea animals—do

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