Lobsters usually develop one smaller, cutter claw and one larger, crus

Question

Lobsters usually develop one smaller, cutter claw and one larger, crusher claw. To show that exercise determines which claw becomes the crusher, researchers placed young lobsters in tanks and repeatedly prompted them to grab a probe with one claw-in each case always the same, randomly selected claw. In most of the lobsters, the grabbing claw became the crusher. But in a second, similar experiment, when lobsters were prompted to use both claws equally for grabbing, most matured with two cutter claws, even though each claw was exercised as much as the grabbing claws had been in the first experiment.

Which of the following is best supported by the information above?

(A) Young lobsters usually exercise one claw more than the other.
(B) Most lobsters raised in captivity will not develop a crusher claw.
(C) Exercise is not a determining factor in the development of crusher claws in lobsters.
(D) Cutter claws are more effective for grabbing than are crusher claws.
(E) Young lobsters that do not exercise either claw will nevertheless usually develop one crusher and one cutter claw.

PyjamaScientist · Answer

Given : Lobsters  usually  develop one smaller, cutter claw and one larger, crusher claw.
Experiment : Either both or only one claw can become a cutter.

Inference : Lobsters usually use one claw more than the other during their infancy. (A) makes the cut. And thus is the correct choice.

milanrajb · Answer

A because it proves that exercise defines the type of claws

PriyamRathor · Answer

Lets try to understand what the question is trying to say :-

GIVEN FACT - Lobsters usually develop one smaller clutter claw and one larger crusher claw.
 Experiments Aim  - To show that exercise determines which claw becomes the crusher.

Experiment 1 :- Young lobsters were repeatedly prompted to use same claw to grab a rope. That claw became the crusher claw.
Conclusion of Exp 1 : Indeed exercise determines which claw becomes the crusher

Experiment 2 :- Young lobsters were prompted to use both claws to grab a rope. Most lobsters matured with clutter claws ( even though each claw was exercised as much as the grabbing claws had been in the first experiment)

Conclusion of Exp 2 : Exercise doesnot determine which claw becomes the crusher claw.(   If that had been the case then in exp 2 both of the claws should become crusher claws  )

Overall Conclusion: - There is some other factor that leads to one claw developing into clutter and the other into crusher.

Question Stem:- What can we infer from the statement above ? ie to find the inference.

Answer Choice Analysis :-

Choice A:-
 Incorrect 
We cannot say this. Second experiment clearly tells us that exercise is not the cause of lobsters developing crusher claws.

Choice B
 Incorrect 
In experiment 1 lobsters developed a crusher claw.

Choice C
 Correct 
In line with our paragraph analysis.

Choice D
 Incorrect 
Paragraph doesnot talk about the effectiveness of the claws.
Irrelevant

Choice E
 Incorrect 
We cannot infer this as nothing has been mentioned about lobsters not exercising.

Thanks
Feedback Appreciated

PyjamaScientist · Answer

Nice analysis Priyam. But, don't you think that the  experiment  did infact   prove   that " exercise " does help in lobsters developing a crusher claw and that one claw can become a crusher claw if that claw is used " more than the other claw "? But, since lobsters are usually found with one crusher claw then, don't you think, it can be inferred that the   young lobsters do infact use one claw more than the other while growing up.   Experiment supports this too.

But, (C) is not what you can infer from the stimulus. As in the first case study when the claws were preferentially treated, one claw attained the nature of a crusher claw. So, "exercise" does infact help in ascertaining nature to lobster's claw.

Posted from my mobile device

PriyamRathor · Answer

Hi  PyjamaScientist ,

So if we take into consideration the conclusion of Experiment 1 in   isolation   then we can surely infer Answer Choice A.
But what about the conclusion of Experiment 2 ? Why the author has mentioned about Experiment 2 ?
Also if we go according to the Experiment 1, the conclusion of Experiment 2 should be that both the claws  become crusher claws not clutter .
Hence experiment 2 contradicts the conclusion of Experiment 1.

Combining both the conclusion we can infer that there is some other factor which leads to lobsters developing a crusher claw and other clutter claw.

Thanks
Feedback Appreciated.

PyjamaScientist · Answer

Hi  PriyamRathor ,

Two points I'd like you to pay attention to:

1. You need to understand that this is an "inference" question not the "main point/main conclusion" question, where the entire stimulus has to have some say in the correct answer choice. In an Inference question, only one part of the stimulus gives you the correct answer choice. So, even though you may feel that Experiment 2 contradicts Experiment 1's result, it is not so.

2. The author has just stated two experiments with two different results. The two results can be called "contradictory" when the initial conditions are kept the same for both the experiments. Here, the author has stated two different conditions, highlighting how lobsters develop crusher claws and cutter claws ( not clutter claws ). So, they are not necessarily contradictory, Experiment 2's result in no way contradicts the finding of Experiment 1 that is if one claw is used more than the other then that claw becomes a crusher claw.

With this understanding, try this question again. Hope it helps.

JCGF2021 · Answer

Hello  Bunuel  could you please provide the official answer to this question? thank you in advance, your replay will be much appreciated.

Mavisdu1017 · Answer

Sorry I think C is the correct answer, cuz in the passage “exercise determines which claw becomes the crusher” is just a conjecture, but NOT a fact. And the results of the 2 experiments which are designed according to the conjecture are contradict, so the conjecture should be wrong.

Choice A assumes the conjecture is a fact. Maybe the development of a crusher claw and a cutter claw has nothing to do with exercising (I mean it is other factors that result in lobsters’ a crusher claw and a cutter claw), since the experiment does not test whether they will develop a crusher claw and a cutter claw when young lobsters exercise one claw more than the other.

Discuss welcomed.

MartyMurray · Answer

Here's choice (C):

(C) Exercise is not a determining factor in the development of crusher claws in lobsters.

Here's what the passage says:

In most of the lobsters, the grabbing claw became the crusher.

We see that exercise can cause a claw to become a crusher claw. Thus, the passage contradicts what choice (C) says.

The passage also says the following:

But in a second, similar experiment, when lobsters were prompted to use both claws equally for grabbing, most matured with two cutter claws

However, that information does not mean that choice (C) is correct. It just means that exercising in a different way does not result in the development of crusher claws. Exercise still can cause a crusher claw to develop as the information earlier in the passage indicates. So, it remains untrue that "exercise is not a determining factor in the development of crusher claws."

Eliminate (C).

VerbalBot · Answer

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Lobsters usually develop one smaller, cutter claw and one larger, crus

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Lobsters usually develop one smaller, cutter claw and one larger, crus

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