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GraceSCKao
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29 Apr 2022, 04:30
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parkhydel
In an attempt to produce a coffee plant that would yield beans containing no caffeine, the synthesis of a substance known to be integral to the initial stages of caffeine production was blocked either in the beans, in the leaves, or both. For those plants in which synthesis of the substance was blocked only in the leaves, the resulting beans contained no caffeine.
Any of the following, if true, would provide the basis for an explanation of the observed results EXCEPT:
A. In coffee plants, the substance is synthesized only in the leaves and then moves to the beans, where the initial stages of caffeine production take place.
B. In coffee plants, the last stage of caffeine production takes place in the beans using a compound that is produced only in the leaves by the substance.
C. In coffee plants, the initial stages of caffeine production take place only in the beans, but later stages depend on another substance that is synthesized only in the leaves and does not depend on the blocked substance.
D. In coffee plants, caffeine production takes place only in the leaves, but the caffeine then moves to the beans.
E. Caffeine was produced in the beans of the modified coffee plants, but all of it moved to the leaves, which normally produce their own caffeine.
Any of the following, if true, would provide the basis for an explanation of the observed results EXCEPT:
A. In coffee plants, the substance is synthesized only in the leaves and then moves to the beans, where the initial stages of caffeine production take place.
B. In coffee plants, the last stage of caffeine production takes place in the beans using a compound that is produced only in the leaves by the substance.
C. In coffee plants, the initial stages of caffeine production take place only in the beans, but later stages depend on another substance that is synthesized only in the leaves and does not depend on the blocked substance.
D. In coffee plants, caffeine production takes place only in the leaves, but the caffeine then moves to the beans.
E. Caffeine was produced in the beans of the modified coffee plants, but all of it moved to the leaves, which normally produce their own caffeine.
Hi avigutman IanStewart
I have checked all the previous posts in this thread, but I I still have some doubts that no one discussed before. So, I decided to write my own post and hope you could share some thoughts and insights when you have time.
1. Does the specific phrasing "the basis for an explanation" play an interesting role in the stem?
Since last time I found that I mistook the boreal owl question as a "typical strengthen-type" CR question and thus neglected the question's exact requirement, getting confused with an incorrect option, I have realized the importance of reading the requirements carefully. Hence, I am not interested in finding out the type for this coffee plant question, but I am intrigued by the phrasing "providing the basis for an explanation of the observed results"--I feel that it is a more delicate requirement than "providing an explanation."
In some CR questions, we are asked to find an explanation or hypothesis that could account for the findings/results. For these questions, the correct answers generally have a strong and direct connection with the results. But I feel that our task is different here. Even though I have no problem with the correct answer--this is an EXCEPT questions, so all options except the correct answer (C) can serve as the basis for an explanation--I feel that some options have a vulnerable connection with the results.
For example:
B. In coffee plants, the last stage of caffeine production takes place in the beans using a compound that is produced only in the leaves by the substance.
->The last stage of caffeine production needs a compound that is produced only in the leaves and that is produced by the substance.
->But we only know that the synthesis of the substance is blocked only in the leaves in this case. We do not know whether the substance can still be produced in the beans, nor do we know whether the substance that is produced in the beans can move to the leave to help develop the compound. If the answers to the two questions are "yes," then the option (B) cannot really explain the results.
For another example:
D. In coffee plants, caffeine production takes place only in the leaves, but the caffeine then moves to the beans.
->Okay, the production occurs only in the leaves, so we do not need to check the production in terms of stages.
->Still, we only know that the synthesis of the substance is blocked only in the leaves in this case--we do not know whether the substance can still be produced in the beans and move to the leave to help the production. If the answers are "yes," it could be inferred that the production would still take place in the leaves and the caffeine would move to the beans as in other normal coffee plant. Then, the option (D) could not explain the results.
I did not want to nitpick with these options on purpose, but I just felt strange that the connection of these options and the results could be undermined--that is not the property of a good explanation in the CR section in my opinion.
But, it occurred to me that I am not looking for "an explanation," but for "a basis for an explanation." This might be why these options are acceptable, as they, with proper addition of information, can still develop into good explanation.
I wonder what you experts would focus on when you are given this requirement. And, when we are asked to find "the basis for an explanation," we do not want to insist that the option should be able to directly explain the results, do we?
2. The substance in question is not known to be essential for all stages of caffeine production, but only for the initial stage of caffeine production--how does this qualification affect our reasoning?
Frankly, I completely neglected the phrasing "initial stages" at my first read, but I noticed this modifier when I tried to evaluate the option (C) and (E) side by side. I could see why the option (E) is better than the option (C), but I do not think (C) absolutely fails to be a basis--it is just not clear enough to me. I wonder how you would interpret the option (C).
C. In coffee plants, the initial stages of caffeine production take place only in the beans, but later stages depend on another substance that is synthesized only in the leaves and does not depend on the blocked substance.
-> Okay, the initial stages of caffeine production takes place only in the beans.
-> We know that the synthesis of the substance essential for the initial stage of production is blocked in the leaves, but we do not know whether the substance could still be produced in the beans.
-> If the answer is "yes," the initial stage of production should go well in the beans despite the blocked synthesis in the leaves, and thus the caffeine would still be produced. Then, the beans should contain the caffeine, since we are not told that the caffeine would move to other parts. This way, the option (C) cannot be the basis for an explanation.
-> If the answer is "no"--the substance essential for the initial stage of production could only be produced in the beans--then the initial stage of production would not go smoothly in the beans, and thus the caffeine should not be produced. This way, the option (C) could actually be a basis.
E. Caffeine was produced in the beans of the modified coffee plants, but all of it moved to the leaves, which normally produce their own caffeine.
->The production takes place in the beans. It is still unclear to us whether the substance could be produced in the beans.
->But whether the answer is "yes" or "no," the beans would not contain the caffeine anyway. If the caffeine is produced, it would move to the leaves, and if the caffeine is not produced because of the blocked synthesis of the substance in the leave, the beans would not contain any caffeine surely.
Separately, I find one part in the option (E) "all of it moved to the leaves, which normally produce their own caffeine." quite tricky--what does it mean? Does it mean that the leaves in the modified coffee plants would normally produce their own caffeine despite the blocked synthesis of the substance? I know we do not need to do inference for this question, but I wonder whether this information suggests that the substance is not only produced in the leaves? The synthesis of the substance is stopped in the leaves, but because the substance can still be synthesized elsewhere and move to the leave, the leave can still produce their own caffeine?
Thank you so much for your thoughts and insights!
avigutman
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Expert reply
29 Apr 2022, 06:18
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GraceSCKao
1. Does the specific phrasing "the basis for an explanation" play an interesting role in the stem?
Since last time I found that I mistook the boreal owl question as a "typical strengthen-type" CR question and thus neglected the question's exact requirement, getting confused with an incorrect option, I have realized the importance of reading the requirements carefully. Hence, I am not interested in finding out the type for this coffee plant question, but I am intrigued by the phrasing "providing the basis for an explanation of the observed results"--I feel that it is a more delicate requirement than "providing an explanation."
In some CR questions, we are asked to find an explanation or hypothesis that could account for the findings/results. For these questions, the correct answers generally have a strong and direct connection with the results. But I feel that our task is different here. Even though I have no problem with the correct answer--this is an EXCEPT questions, so all options except the correct answer (C) can serve as the basis for an explanation--I feel that some options have a vulnerable connection with the results.
For example:
B. In coffee plants, the last stage of caffeine production takes place in the beans using a compound that is produced only in the leaves by the substance.
->The last stage of caffeine production needs a compound that is produced only in the leaves and that is produced by the substance.
->But we only know that the synthesis of the substance is blocked only in the leaves in this case. We do not know whether the substance can still be produced in the beans, nor do we know whether the substance that is produced in the beans can move to the leave to help develop the compound. If the answers to the two questions are "yes," then the option (B) cannot really explain the results.
Actually we do know that the substance cannot be produced in the beans, thanks to "only in the leaves."Since last time I found that I mistook the boreal owl question as a "typical strengthen-type" CR question and thus neglected the question's exact requirement, getting confused with an incorrect option, I have realized the importance of reading the requirements carefully. Hence, I am not interested in finding out the type for this coffee plant question, but I am intrigued by the phrasing "providing the basis for an explanation of the observed results"--I feel that it is a more delicate requirement than "providing an explanation."
In some CR questions, we are asked to find an explanation or hypothesis that could account for the findings/results. For these questions, the correct answers generally have a strong and direct connection with the results. But I feel that our task is different here. Even though I have no problem with the correct answer--this is an EXCEPT questions, so all options except the correct answer (C) can serve as the basis for an explanation--I feel that some options have a vulnerable connection with the results.
For example:
B. In coffee plants, the last stage of caffeine production takes place in the beans using a compound that is produced only in the leaves by the substance.
->The last stage of caffeine production needs a compound that is produced only in the leaves and that is produced by the substance.
->But we only know that the synthesis of the substance is blocked only in the leaves in this case. We do not know whether the substance can still be produced in the beans, nor do we know whether the substance that is produced in the beans can move to the leave to help develop the compound. If the answers to the two questions are "yes," then the option (B) cannot really explain the results.
GraceSCKao
For another example:
D. In coffee plants, caffeine production takes place only in the leaves, but the caffeine then moves to the beans.
->Okay, the production occurs only in the leaves, so we do not need to check the production in terms of stages.
->Still, we only know that the synthesis of the substance is blocked only in the leaves in this case--we do not know whether the substance can still be produced in the beans and move to the leave to help the production. If the answers are "yes," it could be inferred that the production would still take place in the leaves and the caffeine would move to the beans as in other normal coffee plant. Then, the option (D) could not explain the results.
I did not want to nitpick with these options on purpose, but I just felt strange that the connection of these options and the results could be undermined--that is not the property of a good explanation in the CR section in my opinion.
But, it occurred to me that I am not looking for "an explanation," but for "a basis for an explanation." This might be why these options are acceptable, as they, with proper addition of information, can still develop into good explanation.
I wonder what you experts would focus on when you are given this requirement. And, when we are asked to find "the basis for an explanation," we do not want to insist that the option should be able to directly explain the results, do we?
Yes, GraceSCKao, the phrasing "basis for an explanation" is important for the reasons that you stated. We're going to be eliminating any answer choice that is 'heading in a direction that has the potential to explain the observed results'. This is a much lower bar than a full explanation.D. In coffee plants, caffeine production takes place only in the leaves, but the caffeine then moves to the beans.
->Okay, the production occurs only in the leaves, so we do not need to check the production in terms of stages.
->Still, we only know that the synthesis of the substance is blocked only in the leaves in this case--we do not know whether the substance can still be produced in the beans and move to the leave to help the production. If the answers are "yes," it could be inferred that the production would still take place in the leaves and the caffeine would move to the beans as in other normal coffee plant. Then, the option (D) could not explain the results.
I did not want to nitpick with these options on purpose, but I just felt strange that the connection of these options and the results could be undermined--that is not the property of a good explanation in the CR section in my opinion.
But, it occurred to me that I am not looking for "an explanation," but for "a basis for an explanation." This might be why these options are acceptable, as they, with proper addition of information, can still develop into good explanation.
I wonder what you experts would focus on when you are given this requirement. And, when we are asked to find "the basis for an explanation," we do not want to insist that the option should be able to directly explain the results, do we?
GraceSCKao
2. The substance in question is not known to be essential for all stages of caffeine production, but only for the initial stage of caffeine production--how does this qualification affect our reasoning?
This distinction affects our reasoning only within answer choice that break down the caffeine production process into separate stages. If the initial stage isn't possible, then the following stages are also impossible (a chain reaction).GraceSCKao
Frankly, I completely neglected the phrasing "initial stages" at my first read, but I noticed this modifier when I tried to evaluate the option (C) and (E) side by side. I could see why the option (E) is better than the option (C), but I do not think (C) absolutely fails to be a basis--it is just not clear enough to me. I wonder how you would interpret the option (C).
C. In coffee plants, [color=#0000ff]the initial stages of caffeine production take place only in the beans, but later stages depend on another substance that is synthesized only in the leaves and does not depend on the blocked substance.[/color]
-> Okay, the initial stages of caffeine production takes place only in the beans.
-> We know that the synthesis of the substance essential for the initial stage of production is blocked in the leaves, but we do not know whether the substance could still be produced in the beans.
Actually, we can infer that the substance can be produced in the beans.C. In coffee plants, [color=#0000ff]the initial stages of caffeine production take place only in the beans, but later stages depend on another substance that is synthesized only in the leaves and does not depend on the blocked substance.[/color]
-> Okay, the initial stages of caffeine production takes place only in the beans.
-> We know that the synthesis of the substance essential for the initial stage of production is blocked in the leaves, but we do not know whether the substance could still be produced in the beans.
GraceSCKao
E. Caffeine was produced in the beans of the modified coffee plants, but all of it moved to the leaves, which normally produce their own caffeine.
->The production takes place in the beans. It is still unclear to us whether the substance could be produced in the beans.
Actually, we can infer that the substance was produced in the beans. Because if it couldn't be produced in the beans, the modified plants' wouldn't have been able to produce any caffeine.->The production takes place in the beans. It is still unclear to us whether the substance could be produced in the beans.
It's worth noting that the most important words in (C) are "does not depend on", and the most important words in (E) are "all of it."
GraceSCKao
Separately, I find one part in the option (E) "all of it moved to the leaves, which normally produce their own caffeine." quite tricky--what does it mean? Does it mean that the leaves in the modified coffee plants would normally produce their own caffeine despite the blocked synthesis of the substance? I know we do not need to do inference for this question, but I wonder whether this information suggests that the substance is not only produced in the leaves? The synthesis of the substance is stopped in the leaves, but because the substance can still be synthesized elsewhere and move to the leave, the leave can still produce their own caffeine?
No, this doesn't mean that the modified plant's leaves produce their own caffeine. We already know that they're unable to produce the substance integral to the initial stages of caffeine production, so at least those initial stages would have to be done elsewhere. Answer choice (E) suggests that there was still caffeine produced in the modified plants (it was produced in the beans themselves), but *all* of the produced caffeine then moved to the leaves, and that can certainly explain the observed result (the resulting beans contained no caffeine).
29 Apr 2022, 19:19
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Hello everyone, glad to be back on here.
Remember to read the "question stem" (= the assigned task) FIRST—before you read the passage! If you don't, you won't know how to process the text or what to think about as you're reading.
The assigned task here is...
We need something NEW, outside the scope of the currently given statements, to satisfy this prompt.
(This is true whenever the answer choices are described as "if true". Moreover, if you're asked for an "explanation of the observed results", you must not have that explanation yet!)
What are "the observed results"?
—> When we PREVENT the caffeine precursor from being made IN THE LEAVES... the beans don't contain any caffeine.
So, therefore, I WANT some reason why THAT STEP MUST HAPPEN IN THE LEAVES for the beans to become caffeinated.
And don't forget, this is an "ALL EXCEPT" question—so there should be 4 such answers! The one that DOESN'T satisfy this standard is the correct answer.
Let's go one by one.
If the boldfaced part is true, then the leaves are the only place where that step of the process can take place, so this choice satisfies the standard.
We're blocking the step that would create the "compound" in boldface here—so that compound won't be made. Therefore, according to this statement, caffeine production can't run to completion, because the last stage can't happen. This choice satisfies the standard.
Considering the 2 steps described in boldface:
• The first one won't be blocked, because it doesn't happen in the leaves.
• The second won't be blocked either, because, even though it happens in the leaves, it doesn't rely on the step we've blocked.
Our stepwise block has NO definite effect here. This is the CORRECT ANSWER.
If the boldface is true here, then blocking ANY step of caffeine synthesis in the leaves will prevent the beans from becoming caffeinated! This includes the early step we actually are blocking, so, this choice satisfies the standard.
This boldface process can still happen (since we're only blocking synthesis in the leaves, not in the beans).
However, according to this statement, that process will ultimately send caffeine only to the leaves; this caffeine does NOT stay in the beans!
Any other caffeine production would be in the leaves, which we've blocked. So, with this statement, we'll get caffeine-free beans again. This choice satisfies the standard.
It's C
Remember to read the "question stem" (= the assigned task) FIRST—before you read the passage! If you don't, you won't know how to process the text or what to think about as you're reading.
The assigned task here is...
Quote:
Any of the following, if true, would provide the basis for an explanation of the observed results EXCEPT:
We need something NEW, outside the scope of the currently given statements, to satisfy this prompt.
(This is true whenever the answer choices are described as "if true". Moreover, if you're asked for an "explanation of the observed results", you must not have that explanation yet!)
What are "the observed results"?
—> When we PREVENT the caffeine precursor from being made IN THE LEAVES... the beans don't contain any caffeine.
So, therefore, I WANT some reason why THAT STEP MUST HAPPEN IN THE LEAVES for the beans to become caffeinated.
And don't forget, this is an "ALL EXCEPT" question—so there should be 4 such answers! The one that DOESN'T satisfy this standard is the correct answer.
Let's go one by one.
Quote:
A. In coffee plants, the substance is synthesized only in the leaves and then moves to the beans, where the initial stages of caffeine production take place.
If the boldfaced part is true, then the leaves are the only place where that step of the process can take place, so this choice satisfies the standard.
Quote:
B. In coffee plants, the last stage of caffeine production takes place in the beans using a compound that is produced only in the leaves by the substance.
We're blocking the step that would create the "compound" in boldface here—so that compound won't be made. Therefore, according to this statement, caffeine production can't run to completion, because the last stage can't happen. This choice satisfies the standard.
Quote:
C. In coffee plants, the initial stages of caffeine production take place only in the beans, but later stages depend on another substance that is synthesized only in the leaves and does not depend on the blocked substance.
Considering the 2 steps described in boldface:
• The first one won't be blocked, because it doesn't happen in the leaves.
• The second won't be blocked either, because, even though it happens in the leaves, it doesn't rely on the step we've blocked.
Our stepwise block has NO definite effect here. This is the CORRECT ANSWER.
Quote:
D. In coffee plants, caffeine production takes place only in the leaves, but the caffeine then moves to the beans.
If the boldface is true here, then blocking ANY step of caffeine synthesis in the leaves will prevent the beans from becoming caffeinated! This includes the early step we actually are blocking, so, this choice satisfies the standard.
Quote:
E. Caffeine was produced in the beans of the modified coffee plants, but all of it moved to the leaves, which normally produce their own caffeine.
This boldface process can still happen (since we're only blocking synthesis in the leaves, not in the beans).
However, according to this statement, that process will ultimately send caffeine only to the leaves; this caffeine does NOT stay in the beans!
Any other caffeine production would be in the leaves, which we've blocked. So, with this statement, we'll get caffeine-free beans again. This choice satisfies the standard.
It's C
