Each of many different human hormones can by itself raise the

Question

Each of many different human hormones can by itself raise the concentration of glucose in the blood. The reason for this is probably a metabolic quirk of the brain. To see this, consider that although most human cells can produce energy from fats and proteins, brain cells can use only glucose. Thus, if blood glucose levels fall too low, brain cells will rapidly starve, leading to unconsciousness and death.

Which one of the following most accurately expresses the main conclusion of the argument above?

(A) Each of many different human hormones can by itself raise blood glucose levels.

(B) The reason that many different hormones can each independently raise blood glucose levels is probably a metabolic quirk of the brain.

(C) Although most human cells can produce energy from fats and proteins, brain cells can produce energy only from glucose.

(D) If blood glucose levels fall too low, then brain cells starve, resulting in loss of consciousness and death.

(E) The reason brain cells starve if deprived of glucose is that they can produce energy only from glucose.

Source: LSAT and CR archive

GMATGuruNY · Accepted Answer

Premise:
Each of many different human hormones can by itself raise the concentration of glucose in the blood.
Conclusion:
The reason for this is probably a metabolic quirk of the brain: if blood glucose levels fall too low, brain cells will rapidly starve.

Only B correctly paraphrases the conclusion:
 The reason that many different hormones can each independently raise blood glucose levels is probably a metabolic quirk of the brain  (that brain cells will rapidly starve if blood glucose levels fall too low).

B

The other answers choices refer to additional PREMISES: information KNOWN TO BE TRUE.
A conclusion is a statement that is UNPROVEN.
In the passage, only the following statement is unproven:
 The reason for this is PROBABLY a metabolic quirk of the brain .

nightblade354 · Answer

Hi  suyashiitb ,

I can help you there. I, too, fell for (E) my first time around. The key here is the 'because-therefore' trick to determine sub-conclusions and conclusions. But you are correct. 'thus' is a conclusion indicator.

The reason for this is probably a metabolic quirk of the brain .  Thus, if blood glucose levels fall too low, brain cells will rapidly starve, leading to unconsciousness and death.   -- Here are the two portions of the problem in question, separated by color.

BECAUSE this is probably a metabolic quirk of the brain, THEREFORE if blood glucose levels fall too low, brain cells will rapidly starve, leading to unconsciousness and death 
 
 BECAUSE if blood glucose levels fall too low, brain cells will rapidly starve, leading to unconsciousness and death, THEREFORE this is probably a metabolic quirk of the brain. 
 
Which one of the following makes more sense? The second one! Why? Which one of the two statements leads to the other? Is it a brain quirk because of the actions taken, or are the levels falling because it is a quirk?

The 'because-therefore' shows us that the main conclusion will always follow 'therefore', while the sub-conclusion will always follow 'because'

Does this help?

Arro44 · Answer

I have to admit that I struggled quite a bit on this one.

In the end I went for option  B  as it was the only choice I could clearly identify as a conclusion made in the passage.
The other choices focus too much on consequences of certain characteristics, while none of them is wrong they lack the final determination I would like to see from a general conclusion.

I am not perfectly happy with my choice as it is based on more gut-feeling than I would like it to be, but still I would opt for B.

karthik85 · Answer

Looking at the structure of the passage, the opening statement, the way it is presented, is a fact. The second statement is a possible explanation for the phenomenon,i.e the ability of hormones to raise glucose levels. And, it is supported by another fact - i.e brain cells harness energy only from glucose. The other cells are able to harness energy from fats and proteins - again a fact. The last part, with a conclusion marker 'thus' - gives out an obvious consequence - if deprived of glucose,brain cells starve.

Amongst all answer choices, A,C,D, and E are just plain re-statement of the facts already presented in the argument. 
B presents a possible explanation for the ability that many hormones possess - the ability to raise glucose levels individually. Hence B.

nightblade354 · Answer

Good job to all who were able to post excellent responses to the question! Kudos! If anyone has further questions about the topic, please ask!

suyashiitb · Answer

Each of many different human hormones can by itself raise the concentration of glucose in the blood. The reason for this is probably a metabolic quirk of the brain. To see this, consider that although most human cells can produce energy from fats and proteins, brain cells can use only glucose. Thus, if blood glucose levels fall too low, brain cells will rapidly starve, leading to unconsciousness and death.

Which one of the following most accurately expresses the  main conclusion of the argument above ?

Can someone please explain why the E is a bad choice for this question? Isn't the statement followed by "thus" a natural conclusion to the passage? I am still confused.

GMATGuruNY · Answer

To confirm the identify of the conclusion, apply the WHY TEST:
1. State the apparent conclusion.
2. Ask WHY the apparent conclusion is true.
3. The rest of the argument should provide an answer.

E:  The reason brain cells starve if deprived of glucose is that they can produce energy only from glucose. 
 Why is the statement above true? 
 Because  each of many different human hormones can by itself raise the concentration of glucose in the blood.  
This information in red does not provide a logical answer to the question in blue.
Implication:
E is not the conclusion of the argument.
Eliminate E.

B:  The reason that many different hormones can each independently raise blood glucose levels is probably a metabolic quirk of the brain. 
 Why is the statement above true? 
  Because brain cells can use only glucose, and if blood glucose levels fall too low, brain cells will rapidly starve.  
The information in green provide a logical answer to the question in blue.
Implication:
B is the conclusion of the argument.

cycaroline47 · Answer

Everything after "to see this" is extra explanation (i.e. premises) for the main conclusion, so the main conclusion is locked to the first 2 parts of the argument.

ARIEN3228 · Answer

I am not able to wrap my head around this one.

Each of many different human hormones can by itself raise the concentration of glucose in the blood.( fact )

Doesn't this sentence explain how aspect of the first sentence? In CR terminology, isn't the second statement acting as a premise?

analytica233 · Answer

CONCLUSION: The reason for THIS is probably a metabolic quirk of the brain ("This" = that each of many different human hormones can by itself raise the concentration of glucose in the blood). Thus, (B) is correct.

ash124 · Answer

See the word 'probably': It means the author is not sure and he/she is trying to explain the reason. 
Below statements are supported by the rest of the sentences in the argument.
So it is the main conclusion
" Each of many different human hormones can by itself raise the concentration of glucose in the blood. The reason for this is  probably  a metabolic quirk of the brain ."

abhishekmayank · Answer

I am very much confused with this question. Every option seems to be the restatement of what is mentioned in the question stem. Why the option B - which is one of the other restatements in other option - is correct then ?

Mavisdu1017 · Answer

yes I second and I went with E too. There are two conclusions in the stimulus like the boldface type:
(1) The reason for this is probably a metabolic quirk of the brain;
(2) Thus, if blood glucose levels fall too low, brain cells will rapidly starve, leading to unconsciousness and death
If we analyze the relationship of the two above, we will find the second one is an intermediate conclusion while the first one is the final conclusion, so the main conclusion should be the first one.

nedunurianurag · Answer

I feel B is the wrong answer and A is the correct answer. Option A is the main conclusion according to me.

Let's go with each statement

Each of many different human hormones can by itself raise the concentration of glucose in the blood.

The reason for this is probably a metabolic quirk of the brain. -  This is the premise because it supports the fact that human hormones by themselves can raise the concentration of glucose in the blood.

To see this, consider that although most human cells can produce energy from fats and proteins, brain cells can use only glucose. Thus, if blood glucose levels fall too low, brain cells will rapidly starve, leading to unconsciousness and death.  This is like an example that the argument states which can be treated as an additional premise. All it says is since brain cells need glucose and if the glucose falls too low, the cells starve and lead to unconsciousness/death. This essentially is supporting the conclusion on the first line along with the fact that a metabolic quirk is involved

The statement B says that  THE REASON ITSELF  for each of the harmones to raise concentration of glucose is the conclusion

unraveled · Answer

Each of many different human hormones can by itself raise the concentration of glucose in the blood.  The reason for this is probably a metabolic quirk of the brain . To see this, consider that although most human cells can produce energy from fats and proteins, brain cells can use only glucose. Thus, if blood glucose levels fall too low, brain cells will rapidly starve, leading to unconsciousness and death.

Which one of the following most accurately expresses the main conclusion of the argument above?

(A)  Each of many  different human hormones can by itself raise blood glucose levels.

(B) The reason that many different hormones can each independently raise blood glucose levels is probably a metabolic quirk of the brain.

(C) Although most human cells can produce energy from fats and proteins, brain cells can produce energy only from glucose.

(D) If blood glucose levels fall too low, then brain cells starve, resulting in loss of consciousness and death.

(E) The reason brain cells starve if deprived of glucose is that they can produce energy only from glucose.

I fell flat by this question, especially by question stem.
I was sure that highlighted text was quite a jump that the argument made from first statement but i was not able to figure out what exactly it was trying to make. Further it elaborates in the third sentence to give an idea about the quirk.

E was right away my choice, something that I should not have gone for instead of POE. E is just like C, thus here itself E could have been eliminated. D is again a restatement. 'Each of many' in A is almost like 'most', so again a restatement.
All in all, i could understand that each of the options except B are stating what is already stated in the argument. From that point of view as well B can be marked but this is more of a gut feeling that actual analysis of the argument.

Answer B.

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