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Many important types of medicine have been developed from substances 13 Jun 2020, 20:02
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Type: Find the assumption

Conclusion: if the tropical rain forests are not preserved, important types of medicine will never be developed.


(A) There are substances of medicinal value contained in tropical rain forest plants not yet studied by scientists that differ from those substances already discovered in tropical rain forest plants. - if the yet-to-be-studied plants do not have any medicinal value, then preserving the forests will not lead to the development of new medicines. this would therefore weaken the conclusion cited. Hence, (A) is the assumption that is required to support the conclusion drawn. Therefore, (A) is the right answer choice.

(B) Most of the tropical rain forest plants that contain substances of medicinal value can also be found growing in other types of environment. - (B) actually weakens the conclusion, not strengthen it.

(C) The majority of plant species that are unique to tropical rain forests and that have been studied by scientists have been discovered to contain substances of medicinal value. - talks about what has already been discovered; but the conclusion deals with those medicines that have not been developed yet.

(D) Any substance of medicinal value contained in plant species indigenous to tropical rain forests will eventually be discovered if those species are studied by scientists. - irrelevant to the conclusion.

(E) The tropical rain forests should be preserved to make it possible for important medicines to be developed from plant species that have not yet been studied by scientists. - simply restates what's already mentioned in the passage.
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Many important types of medicine have been developed from substances 16 Jun 2020, 02:39
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Many important types of medicine have been developed from substances discovered in plants that grow only in tropical rain forests. There are thousands of plant species in these rain forests that have not yet been studied by scientists, and it is very likely that many such plants also contain substances of medicinal value. Thus, if the tropical rain forests are not preserved, important types of medicine will never be developed.

Which one of the following is an assumption required by the argument?


(A) There are substances of medicinal value contained in tropical rain forest plants not yet studied by scientists that differ from those substances already discovered in tropical rain forest plants.

(B) Most of the tropical rain forest plants that contain substances of medicinal value can also be found growing in other types of environment.

(C) The majority of plant species that are unique to tropical rain forests and that have been studied by scientists have been discovered to contain substances of medicinal value.

(D) Any substance of medicinal value contained in plant species indigenous to tropical rain forests will eventually be discovered if those species are studied by scientists.

(E) The tropical rain forests should be preserved to make it possible for important medicines to be developed from plant species that have not yet been studied by scientists.
Show more


Why are other choices wrong?

B) Weakener. (The argument says that if important types of medicines are developed, tropical rain forests MUST be preserved. This choice says that there are other sources)
C) Strengthener. Not a Must have. Do we NEED that more than 50 percent of such plant species were found to contain substances of medicinal value?
D) Strengthener. Extreme version of choice C. Do we NEED that more than 100 percent of such plant species will yield medicinal value?
E) No impact. It is almost the conclusion. Why do I say almost? Because the statement uses the word 'should' that has an aspect of moral obligation assigned to it. However, the conclusion is that the Tropical rain forests MUST be preserved to make it possible for important medicines to be developed from plant species that have not yet been studied by scientists.
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Many important types of medicine have been developed from substances 28 Jun 2020, 09:54
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Can some expert please reply as to why option D is not correct.
If the substances cannot be found by the scientists then important types of substances will never be developed?

Even I have the same doubt... Can anyone explain, Why D is incorrect? GMATNinja GMATNinjaTwo
The conclusion of this argument is: If the tropical rain forests are not preserved, important types of medicine will never be developed.

Here's how the author gets to this conclusion:

  • Many important types of medicine have been developed from substances found in plants -- specifically, plants that only grow in tropical rainforests.
  • Thousands of plant species in these rain forests have not yet been studied by scientists.
  • It's very likely that many of those plant species contain substances of medicinal value.
  • So if the tropical rainforests are not preserved, then important types of medicine (made from substances inside tropical rain forest plants) will never be developed.

We're asked if choice (D) is an assumption required by the argument. Let's take a close look at (D) to decide:

Quote:
(D) Any substance of medicinal value contained in plant species indigenous to tropical rain forests will eventually be discovered if those species are studied by scientists.
"Any substance" here has the same meaning as "every substance" or "all substances." So according to choice (D), if any substance at all has medicinal value, then that substance will eventually be discovered. In other words, every single substance of medicinal value will be discovered.

But does the conclusion really assume that every single substance of medicinal value will be discovered upon study?

No. Scientists do not have to discover every single substance of medicinal value in order to develop important types of medicine. Put another way, scientists can develop important types of medicine after studying fewer than 100% of the plants that contain these substances. Nothing we've read in the argument suggests otherwise.

Compare this to choice (A):

Quote:
(A) There are substances of medicinal value contained in tropical rain forest plants not yet studied by scientists that differ from those substances already discovered in tropical rain forest plants.
This choice recognizes that medicinally valuable substances have already been discovered in tropical rain forest plants. What the conclusion really requires is that some substances in tropical rain forest plants are different from the ones already discovered.

Choice (A) calls out this requirement, as obvious as it might seem. And this choice doesn't slip up by saying something like, "All substances of medicinal value contained in tropical rain forest plants not yet studied by scientists differ from those substances already discovered in tropical rain forest plants." That change in wording would make this answer choice just as wrong as (D).

That's why we eliminate (D) and stick with (A).

I hope this helps!

GMATNinja - For choice D, since it says "eventually" doesn't it seem like one of the assumptions?
If we preserve the rainforests for a very long time (infinity years), then eventually (i.e. over a very long time) the other plants species and their medicinal value can be discovered by scientists.
How do you interpret that time frame "eventually"?

Can you show how to eliminate D using the negation technique?

Here is my thinking:

"Any substance of medicinal value contained in plant species indigenous to tropical rain forests will eventually be discovered if those species are studied by scientists."

Negate - Any substance of medicinal value contained in plant species indigenous to tropical rain forests will NOT eventually be discovered if those species are studied by scientists.
So, we don't need to preserve rainforests and the argument falls apart, making this a correct assumption.

Thanks!
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This question is actually an excellent example of the limitations of using the negation technique. While the negation technique is logically sound, it can be difficult to determine what exactly to negate. In this instance it’s much easier just to think about what an assumption is: something that, while left unstated in the passage, must be true for the conclusion to be properly drawn.

With that in mind, borrowing from my previous post, does it have to be true that every single substance of medicinal value will eventually be discovered in order to conclude that important types of medicine will never be developed if the forests are not preserved?

No. The conclusion still follows even if just some of the potentially valuable medicinal substances are discovered. For that reason, we can eliminate (D).

I hope that helps!
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Many important types of medicine have been developed from substances 01 Jul 2020, 04:55
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My take on this ---
Read the first line and the last line

Many medicines have been developed ---- First line
Many different types of medicine would not be developed --- Last line

Hence key assumption would be that the plants not studied have medicinal values different from what we have found today

Hence A

Option D is a close answer choice. But it conveys a harsh meaning that all need to be studied. Even if one is studied it will fulfill the conclusion only if it is different from what has been studied.

Hence D is an assumption but not the most appropriate.
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Many important types of medicine have been developed from substances 18 May 2021, 05:41
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Biodiversity of the tropical rainforest

There is variation. It has no consistency. Some areas are not varied much and others vary. You have to understand there are many such forests. Having been in one on Luzon, I could tell you it was not highly varied but I could not even tell you all of that island.

I have traveled the island quite a bit. This is not to tell you that I don’t know a lot but I could hardly say it is consistent with all of the island. I have been all the way from Manila to Pagudpud to Bataan to Baguio to Pudtol and many points in between. I have noticed that the place was quite limited in differentiation of species. It was hardly comparable to where I live in Alabama which has about 350 species of large bole trees within a few miles and 3,000 small bole tree species. It is something I always am observing. Botany stuff is fascinating to me.

The Filipino people frustrated me because of their generalized lack of attention to plants etc. It was very hard to get information on observed plants. They seemed almost oblivious to the issues of such variety etc. I guess I am a bit odd in that I am very curious about such.

The species differentiation is mostly by altitude in that area. Below about 1500 meters the forest is pretty consistent. Above that the forest was mostly pines. There were about 5 or 10 varieties of pines. Below that the forest was largely Mahogany and several other species (10 or 15) large bole trees. The small bole trees I would estimate I saw about 100 varieties. The areas also had bamboo. It is a curious fact that bamboo which is a grass it is botanically classified very stupidly. Bamboo definitely had several thousand varieties but botanically that is ranked as at most few varieties. I would say that bamboo is classified like if I said GRASS. That is just wrong.

Low altitude trees were highly selected for commercial value such a Mangos or Tamarind or Palms. Below about 200 meters the island has been highly cleared. They also had 3 imported species of pulpwood crop trees. Luzon is involved in a determined reforestation effort. I have seen the nursery for the seedlings and there were 5 varieties being pushed into replanting. The natural propagation of trees on Luzon is quite slow. It is stunningly slow compared to temperate zone growth.

As to my comments on Bamboo, I can tell you that there are varieties of bamboo that are naturally short, medium or tall. Thin wall, thick wall medium wall and more. Bamboo comes in broad leafy varieties and narrow leafy varieties. The bamboo can be anywhere from about 1/2 inch diameter to about 12 inch diameter and it can be segmented with solid cores or cores which have holes in them. It comes in several colors. It comes in different heights as well. Bamboo is not just bamboo. It definitely needs a full scale botanical reclassification. The reasons for this are that bamboos are a clumpy rhizome grass that has a definite preference based upon variety for certain soils etc. All of these factors define culturing and harvesting and conservation of this grass. The growers in the USA define at least 25 varieties and to be fair my guess is that there are over 3,000.

Owners of a bamboo in the Philippines take some high pride in their particular plants. Single bamboo plants can cover several hectares and exclude all other plants as the species is very aggressive. Bamboo plants are similar to annual grass in their life cycle but it can be over 100 years. Some plants bloom and die regrowing from seed. Bamboo plants are of very high value to the people of the Island of Luzon.

As you can see I do observe the plants pretty highly in detail but frankly I cannot say my observation is by any means complete. Luzon is most definitely a tropical rainforest. It has elevations from sea level to well above 4,000 meters. It has many varied soils because the island is the site of so many geologic events from sedimentation to volcanism.

I also could not tell you that the forest of South America or Africa or Borneo or New Guinea or any number of other places are or are not similar.
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Many important types of medicine have been developed from substances 04 Aug 2021, 05:32
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Biodiversity of the tropical rainforest

There is variation. It has no consistency. Some areas are not varied much and others vary. You have to understand there are many such forests. Having been in one on Luzon, I could tell you it was not highly varied but I could not even tell you all of that island.

I have traveled the island quite a bit. This is not to tell you that I don’t know a lot but I could hardly say it is consistent with all of the island. I have been all the way from Manila to Pagudpud to Bataan to Baguio to Pudtol and many points in between. I have noticed that the place was quite limited in differentiation of species. It was hardly comparable to where I live in Alabama which has about 350 species of large bole trees within a few miles and 3,000 small bole tree species. It is something I always am observing. Botany stuff is fascinating to me.

The Filipino people frustrated me because of their generalized lack of attention to plants etc. It was very hard to get information on observed plants. They seemed almost oblivious to the issues of such variety etc. I guess I am a bit odd in that I am very curious about such.

The species differentiation is mostly by altitude in that area. Below about 1500 meters the forest is pretty consistent. Above that the forest was mostly pines. There were about 5 or 10 varieties of pines. Below that the forest was largely Mahogany and several other species (10 or 15) large bole trees. The small bole trees I would estimate I saw about 100 varieties. The areas also had bamboo. It is a curious fact that bamboo which is a grass it is botanically classified very stupidly. Bamboo definitely had several thousand varieties but botanically that is ranked as at most few varieties. I would say that bamboo is classified like if I said GRASS. That is just wrong.

Low altitude trees were highly selected for commercial value such a Mangos or Tamarind or Palms. Below about 200 meters the island has been highly cleared. They also had 3 imported species of pulpwood crop trees. Luzon is involved in a determined reforestation effort. I have seen the nursery for the seedlings and there were 5 varieties being pushed into replanting. The natural propagation of trees on Luzon is quite slow. It is stunningly slow compared to temperate zone growth.

As to my comments on Bamboo, I can tell you that there are varieties of bamboo that are naturally short, medium or tall. Thin wall, thick wall medium wall and more. Bamboo comes in broad leafy varieties and narrow leafy varieties. The bamboo can be anywhere from about 1/2 inch diameter to about 12 inch diameter and it can be segmented with solid cores or cores which have holes in them. It comes in several colors. It comes in different heights as well. Bamboo is not just bamboo. It definitely needs a full scale botanical reclassification. The reasons for this are that bamboos are a clumpy rhizome grass that has a definite preference based upon variety for certain soils etc. All of these factors define culturing and harvesting and conservation of this grass. The growers in the USA define at least 25 varieties and to be fair my guess is that there are over 3,000.

Owners of a bamboo in the Philippines take some high pride in their particular plants. Single bamboo plants can cover several hectares and exclude all other plants as the species is very aggressive. Bamboo plants are similar to annual grass in their life cycle but it can be over 100 years. Some plants bloom and die regrowing from seed. Bamboo plants are of very high value to the people of the Island of Luzon.

As you can see I do observe the plants pretty highly in detail but frankly I cannot say my observation is by any means complete. Luzon is most definitely a tropical rainforest. It has elevations from sea level to well above 4,000 meters. It has many varied soils because the island is the site of so many geologic events from sedimentation to volcanism.

I also could not tell you that the forest of South America or Africa or Borneo or New Guinea or any number of other places are or are not similar.
Show more

That is something.
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Many important types of medicine have been developed from substances 13 Jan 2022, 07:47
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Not totally convinced with answers given for why D is wrong. The argument says it is important to save tropical forests in order to develop imp. medicines . So if the scientists could not discover the medicinal values , then there is no point of saving the forest. Hence, the obvious assumption is scientist will discover the medicinal values.

Whereas as per A , even if we assume that the medicinal values in plants are different than those plants which have already been discovered, but if the scientists could not discover these new medicinal values. Again , preserving the forest does nothing.

Can anyone explain why D is wrong without giving vague answers
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Many important types of medicine have been developed from substances 19 Jan 2022, 10:50
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Not totally convinced with answers given for why D is wrong. The argument says it is important to save tropical forests in order to develop imp. medicines . So if the scientists could not discover the medicinal values , then there is no point of saving the forest. Hence, the obvious assumption is scientist will discover the medicinal values.

Whereas as per A , even if we assume that the medicinal values in plants are different than those plants which have already been discovered, but if the scientists could not discover these new medicinal values. Again , preserving the forest does nothing.

Can anyone explain why D is wrong without giving vague answers
Show more
The question asks us for an assumption required by the argument. In other words, which option absolutely MUST be assumed in order for the argument to hold up?

That's very different from finding an "obvious" assumption, and the details in the answer choices really matter.

So, to reach his/her conclusion ("If the tropical rain forests are not preserved, important types of medicine will never be developed,") does the author absolutely HAVE to assume (D)?

Here it is:
Quote:
(D) Any substance of medicinal value contained in plant species indigenous to tropical rain forests will eventually be discovered if those species are studied by scientists.
Show more
As we mentioned in this post, the issue with (D) is the word "any," which has the same meaning as "every substance" or "all substances."

Does the author HAVE to assume that ALL substances of medicinal value will be discovered?

Nope, he/she does not. It would be enough for just SOME substances of medicinal value to be discovered for the author's argument to hold up.

Because (D) doesn't absolutely HAVE to be true, it's not an assumption required by the argument.

And here's (A):
Quote:
(A) There are substances of medicinal value contained in tropical rain forest plants not yet studied by scientists that differ from those substances already discovered in tropical rain forest plants.
Show more
Again, we're looking for something that MUST be true in order for the author's conclusion to have a shot at holding up. (A) is that thing -- we MUST assume that there are different substances out there for the author's conclusion to hold any water.

As you've mentioned, (A) doesn't guarantee that new medicines will be discovered -- but we're not looking for a guarantee. We're looking for something that is required by the argument, even if it's just one piece of the puzzle.

The argument falls apart without assuming (A), so (A) is the assumption required by the argument.

I hope that helps!
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Many important types of medicine have been developed from substances 10 Apr 2024, 15:02
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Understanding the argument - ­
Many important types of medicine have been developed from substances discovered in plants that grow only in tropical rainforests. - Background info. 
There are thousands of plant species in these rainforests that have not yet been studied by scientists, and it is very likely that many such plants also contain substances of medicinal value. - opinion. 
Thus, if the tropical rainforests are not preserved, important types of medicine will never be developed. - Conclusion. 

Sufficient condition - If X, then Y means X implies Y, or not Y implies not X. 
If the tropical rainforests are not preserved, then important types of medicine will never be developed. 
--> lack of preservation of typical rainforests --> implies --> important medicines will never be developed. 

If not X, then not Y, translates to only if X, Y. Only if rainforests are preserved, important medicines will be developed. 
This means "the preservation of rainforests" is a minimum condition for the development of important medicines.  By the way, if we are meeting the minimum condition, does that mean that important medicines will be developed? No. We need the missing premise that the additional preserved plants will have further substances of medicinal use. 

Y implies X, meaning the development of important medicines implies the preservation of rainforests. 

But do we already have some of the medicines developed? Isnt it? Yes. So essentially, we are talking about new medicines, and we assume that the remaining plants will have additional substances to develop additional important medicines. 

Which one of the following is an assumption required by the argument?

Option Elimination - We need to find the missing premise, minimum requirement, or assumption. 

(A) There are substances of medicinal value contained in tropical rainforest plants not yet studied by scientists that differ from those substances already discovered in tropical rainforest plants. - ok. 

(B) Most of the tropical rain forest plants that contain substances of medicinal value can also be found growing in other types of environment. - "Other types of environment" are out of scope. Even if we take it for the existing medicines, at best, it's a weakener. 

(C) The majority of plant species that are unique to tropical rain forests and that have been studied by scientists have been discovered to contain substances of medicinal value. - "that has been studied by scientists" is out of scope. We are concerned about the new ones. 

(D) Any substance of medicinal value contained in plant species indigenous to tropical rain forests will eventually be discovered if those species are studied by scientists. - Just add another conditional for no reason. Moreover, we aren't concerned about "all substances of medicinal value will eventually be discovered." We are concerned that we preserve tropical rainforests so that scientists get time to study them, and they are of value. 

(E) The tropical rain forests should be preserved to make it possible for important medicines to be developed from plant species that have not yet been studied by scientists. - Opinion. Not a premise. 
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Many important types of medicine have been developed from substances 28 May 2025, 15:19
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But isnt the conclusion in the question loosely stated? It states that preservation is required for producing all types of medicines (made form plants in rain forest). So preservation is required whther the remaining forest plant doesnt helps in making new medicine or not.
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GptShubham
Quote:
Can some expert please reply as to why option D is not correct.
If the substances cannot be found by the scientists then important types of substances will never be developed?

Even I have the same doubt... Can anyone explain, Why D is incorrect? GMATNinja GMATNinjaTwo
The conclusion of this argument is: If the tropical rain forests are not preserved, important types of medicine will never be developed.

Here's how the author gets to this conclusion:

  • Many important types of medicine have been developed from substances found in plants -- specifically, plants that only grow in tropical rainforests.
  • Thousands of plant species in these rain forests have not yet been studied by scientists.
  • It's very likely that many of those plant species contain substances of medicinal value.
  • So if the tropical rainforests are not preserved, then important types of medicine (made from substances inside tropical rain forest plants) will never be developed.

We're asked if choice (D) is an assumption required by the argument. Let's take a close look at (D) to decide:

Quote:
(D) Any substance of medicinal value contained in plant species indigenous to tropical rain forests will eventually be discovered if those species are studied by scientists.
"Any substance" here has the same meaning as "every substance" or "all substances." So according to choice (D), if any substance at all has medicinal value, then that substance will eventually be discovered. In other words, every single substance of medicinal value will be discovered.

But does the conclusion really assume that every single substance of medicinal value will be discovered upon study?

No. Scientists do not have to discover every single substance of medicinal value in order to develop important types of medicine. Put another way, scientists can develop important types of medicine after studying fewer than 100% of the plants that contain these substances. Nothing we've read in the argument suggests otherwise.

Compare this to choice (A):

Quote:
(A) There are substances of medicinal value contained in tropical rain forest plants not yet studied by scientists that differ from those substances already discovered in tropical rain forest plants.
This choice recognizes that medicinally valuable substances have already been discovered in tropical rain forest plants. What the conclusion really requires is that some substances in tropical rain forest plants are different from the ones already discovered.

Choice (A) calls out this requirement, as obvious as it might seem. And this choice doesn't slip up by saying something like, "All substances of medicinal value contained in tropical rain forest plants not yet studied by scientists differ from those substances already discovered in tropical rain forest plants." That change in wording would make this answer choice just as wrong as (D).

That's why we eliminate (D) and stick with (A).

I hope this helps!
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Many important types of medicine have been developed from substances 30 Jun 2025, 09:23
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ekanshgoyal
But isnt the conclusion in the question loosely stated? It states that preservation is required for producing all types of medicines (made form plants in rain forest). So preservation is required whther the remaining forest plant doesnt helps in making new medicine or not.
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The conclusion is: "if the tropical rain forests are not preserved, important types of medicine will never be developed." We aren't concerned with medicines that already exist, since those have already been developed.

If we replace the word "developed" with "produced" in the conclusion, that would be a different story. In that case, (A) would not matter. But the argument is not concerned with the production of medicines that have already been developed. Once a medicine has been developed, it can be produced, but it cannot be developed again. So the argument is only concerned with new medicines.

I hope that helps!
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Many important types of medicine have been developed from substances 13 Jul 2025, 04:31
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I selected A, and it took me around 3 min 30 sec to find the answer. Can anyone guide me how to find correct answer within 2 mins if options are lengthy like we have in this question?
akela
Many important types of medicine have been developed from substances discovered in plants that grow only in tropical rain forests. There are thousands of plant species in these rain forests that have not yet been studied by scientists, and it is very likely that many such plants also contain substances of medicinal value. Thus, if the tropical rain forests are not preserved, important types of medicine will never be developed.

Which one of the following is an assumption required by the argument?


(A) There are substances of medicinal value contained in tropical rain forest plants not yet studied by scientists that differ from those substances already discovered in tropical rain forest plants.

(B) Most of the tropical rain forest plants that contain substances of medicinal value can also be found growing in other types of environment.

(C) The majority of plant species that are unique to tropical rain forests and that have been studied by scientists have been discovered to contain substances of medicinal value.

(D) Any substance of medicinal value contained in plant species indigenous to tropical rain forests will eventually be discovered if those species are studied by scientists.

(E) The tropical rain forests should be preserved to make it possible for important medicines to be developed from plant species that have not yet been studied by scientists.
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