Rhizobium bacteria living in the roots of bean plants or other legumes

between B and E.
B. Fixed nitrogen is currently the only soil nutrient that must be supplied by artificial fertilizer for growing wheat crops. (conclusion says that it will just reduce need in fertilizer, so this assumption is wrong)
E. Rhizobium bacteria living in the roots of wheat would produce fixed nitrogen (it remove the gap between last premise and conclusion, so correct)

Premise
Rhizobium bacteria living in the roots of bean plants or other legumes produce fixed nitrogen which is one of the essential plant nutrients and which for non-legume crops, such as wheat, normally must be supplied by applications of nitrogen-based fertilizer.

Conclusion:
So if biotechnology succeeds in producing wheat strains whose roots will play host to Rhizobium bacteria, the need for artificial fertilizers will be reduced.
The argument above makes which one of the following assumptions?
>>RB would maintain the same behavior in the roots of other plants.

(A) Biotechnology should be directed toward producing plants that do not require artificial fertilizer.
(B) Fixed nitrogen is currently the only soil nutrient that must be supplied by artificial fertilizer for growing wheat crops.
(C) There are no naturally occurring strains of wheat or other grasses that have Rhizobium bacteria living in their roots.
(D) Legumes are currently the only crops that produce their own supply of fixed nitrogen.
(E) Rhizobium bacteria living in the roots of wheat would produce fixed nitrogen.
>>Correct.Negating it puts the conclusion in doubt.

Close call between B and E .

But negate E , If Rhizobium bacteria living in the roots of wheat Can not produce fixed nitrogen , then argument falls apart.
So answer is E.

The Argument doesnt talk anything about the types of explosion..hence its quite out of scope to include them

Use the word “Explosion” = desirable reactions = discussed well served
Use the word “Energetic disassembly” = NO desirable reactions = discussion Not well served

Conclusion: Use the word "Explosion" throughout in the discussion.

Possible assumptions:
1) Only those terms concerning "Desirable reactions" find place throughout the discussion.
2) Only those discussions that are well served are used throughout the discussion.

Choice A is correct.

P.S.: I had initially chosen choice C , but then I realised that it does not bridge the gap between the premise and conclusion, which is why to use the word "Explosion" throughout in the discussion.

In Choice B, It said that It has revised the scale, but it did not say whether it is increased or decreased. If it is increased the level (less strict) then it must have gone down in 2012. If its the opposite then the argument is not true. Hence I chose this answer. I can see that C is much stronger and its not linked with city at all.

Can anyone suggest why B is wrong?

Thanks,
G.

I see what you mean about B. They could have revised the scale for what is unhealthful. But that would require an assumption that the scale of pollutants measured by gas spectrography is the same scale as the health indicator scale. That is, the range of what is measured by spectrography may be much larger than the range of what is considered healthy.

Rhizobium bacteria living in the roots of bean plants or other legumes produce fixed nitrogen which is one of the essential plant nutrients and which for non-legume crops, such as wheat, normally must be supplied by applications of nitrogen-based fertilizer. So, if biotechnology succeeds in producing wheat strains whose roots will play host to Rhizobium bacteria, the need for artificial fertilizers will be reduced.

Conclusion: So, if biotechnology succeeds in producing wheat strains whose roots will play host to Rhizobium bacteria, the need for artificial fertilizers will be reduced.

Falsification Situation(s):
1) What if the Rhizobium bacteria have some adverse effects on wheat plants? What if those adverse effects offset the benefit that the wheat plant draws from nitrogen?
2) What if the Rhizobium bacteria fail to survive on wheat plants for some reason X.

Possible Assumptions:
1) There are no adverse effects of Rhizobium bacteria on wheat plants.
2) The Rhizobium bacteria can survive on the roots of wheat plants and are able to produce the nitrogen.

The argument above makes which one of the following assumptions?

(A) Biotechnology should be directed toward producing plants that do not require artificial fertilizer.
That’s a very broad assumption. This cannot be the assumption. If it were true, then why the argument talks about such a specific case?

(B) Fixed nitrogen is currently the only soil nutrient that must be supplied by artificial fertilizer for growing wheat crops.
Negate: Fixed nitrogen is not the only soil nutrient that must be supplied by artificial fertilizer for growing wheat crops.
If this were true, then the need for artificial fertilizers may not come down. This negated statement has the potential to break down the conclusion. This option is a possible assumption.


(C) There are no naturally occurring strains of wheat or other grasses that have Rhizobium bacteria living in their roots.
Negate: There are some naturally occurring strains of wheat or other grasses that have Rhizobium bacteria living in their roots.
1) …or other grasses do not affect conclusion
2) If only 1 in 100 has this feature, then no way this information breaks the conclusion.
This option cannot be an assumption.

(D) Legumes are currently the only crops that produce their own supply of fixed nitrogen.
It does not talk about that non-legumes, therefore it cannot be an assumption.

(E) Rhizobium bacteria living in the roots of wheat would produce fixed nitrogen.
Negate: Rhizobium bacteria living in the roots of wheat would not produce fixed nitrogen.
This breaks the conclusion. This is an assumption.

Between B and E – what if the other nutrients required are not in significant quantity? Then, the application of the fertilizers can be reduced but if the bacteria are not able to produce the nitrogen at the first place, the whole conclusion breaks. Thus, option E.

Sentence 1 (premise): Rhizobium bacteria grows in beans, and other plants that are characterized as legumes, producing fixed nitrogen which is an essential plant nutrient. Other crops, that are not characterized as legumes, such as wheat must have this fixed nitrogen supplied to it through nitrogen based fertilizer.

Sentence 2 (conclusion): If technology could produce a wheat crop which would naturally play host to rhizobium bacteria then the need for the artificial fertilizers would be reduced.

What is an assumption this argument depends upon?

Okay so let's find some gaps in the reasoning. First of all the author is assuming that if they created a wheat crop that could play host to rhizobium bacteria that they would not have to rely on an equal or greater amount of "artificial fertilizer" in order to introduce the bacteria into the roots of the wheat crop. The second gap I can see is that the author assumes that the production of the wheat crop which could host rhizobium bacteria would not result in the creation of some sort of unpredictable issue in which there is an additional need for a great or equal amount of artificial fertilizer. Let's take a look at the answer choices.

(A) "towards producing plants" The author is only making an argument for a specific type of plant "non-legume crops". This answer choice is too broad to qualify as a necessary assumption. Even if it narrowed it's scope to "non-legume crops such as wheat" it would still not qualify as a necessary assumption, because the author's argument states "if biotech. succeeds in producing wheat strains which can play host to rhizobium . . ." He introduces a conditional logic statement into the conclusion, and does not conclude anything about what biotechnology "must do" but rather a result (need for artificial fertilizers reduced) if biotech. succeeds in producing a wheat strain that can host rhizobium bacteria.
(B) This is tempting. However, remember the arguments conclusion focuses on "the need for artificial fertilizers will be reduced." If you negate this answer choice it reads "Fixed nitrogen is not the only soil nutrient supplied by artificial fertilizers." The negation of this statement is too ambiguous to be able to discern the impact. One can imagine 2 scenarios taking place if this answer choice were negated.
1. There is no reduction in the amount of artificial fertilizer, because artificial fertilizer is still required to supply other nutrients to the wheat crop. or 2. There is a reduction in the amount of artificial fertilizer, because wheat crops are getting their fixed nitrogen from rhizobium bacteria and so depend on a smaller amount of artificial fertilizer.
(C) "There are no naturally occurring strains of wheat . . ." The stimulus only makes the claim that "wheat normally must be supplied by applications of nitrogen based fertilizer." This leaves open the possibility that some wheat strains might be able to produce fixed nitrogen. This answer choice is unsupported and definitely not a necessary assumption. Get rid of it.
(D) ". . . the only crops that produce their own supply of fixed nitrogen. . ." This is also unsupported. We know that legumes do produce fixed nitrogen, but nowhere in the stimulus can you find any support that legumes are the only crops that naturally produced fixed nitrogen. Get rid of this.
(E) This is the correct answer choice. Remember the author conclusion is that "the need for artificial fertilizer will be reduced if wheat strains could host rhizobium bacteria which produce fixed nitrogen." If you negate the answer choice it would read "Rhizobium bacteria living in the roots of wheat would not produce fixed nitrogen." If that were the case then the authors argument would be blown out of the water, because he/she could not conclude that there can be any kind of reduction of artificial fertilizer based on the ability of wheat crops to host rhizobium bacteria as the rhizobium in the wheat crops would not be able to produce fixed nitrogen. Let me know if you need further clarification on this.
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(B) Fixed nitrogen is currently the only soil nutrient that must be supplied by artificial fertilizer for growing wheat crops.
If we negate (B), it becomes: "Fixed nitrogen is currently NOT THE ONLY soil nutrient that must be supplied by artificial fertilizer for growing wheat crops". Note that the argument says that "non-legume crops, such as wheat, normally must be supplied by applications of NITROGEN-BASED fertilizer". So even if the wheat crop needs other nutrients that must be supplied by artificial fertilizers, thanks to the successful application of biotechnology the wheat crop will NO LONGER need nitrogen-based fertilizer, thereby reducing the OVERALL NEED for artificial fertilizers. Hence, (B) is not the assumption and therefore incorrect.
Final note: If the arguments said that "non-legume crops, such as wheat, normally must be supplied nitrogen by ARTIFICAL FERTILIZERS", then (B) would be an assumption.

(A) Biotechnology should be directed toward producing plants that do not require artificial fertilizer. -- Incorrect. Doesn't affect the conclusion in any manner which is about reducing the need for artificial fertilisers due to supply of nitrogen through the use of biotech.

(B) Fixed nitrogen is currently the only soil nutrient that must be supplied by artificial fertilizer for growing wheat crops. -- Incorrect. Negating this would fixed nitrogen is not the only soil nutrient. It doesn't destroy conclusion since demand could still be lowered through biotechnology.

(C) There are no naturally occurring strains of wheat or other grasses that have Rhizobium bacteria living in their roots. -- Incorrect. Even if there are some strains, bio-tech can still do its magic and provide increased fixed nitrogen.

(D) Legumes are currently the only crops that produce their own supply of fixed nitrogen. -- Incorrect. Completely irrelevant to the conclusion.

(E) Rhizobium bacteria living in the roots of wheat would produce fixed nitrogen. -- Correctly. Negating this would destroy the conclusion. If RB does not produce fixed nitrogen once transplanted into the wheat crops, then fertiliser usage will not go down.

Rhizobium bacteria living in the roots of bean plants or other legumes produce fixed nitrogen which is one of the essential plant nutrients and which for non-legume crops, such as wheat, normally must be supplied by applications of nitrogen-based fertilizer. So if biotechnology succeeds in producing wheat strains whose roots will play host to Rhizobium bacteria, the need for artificial fertilizers will be reduced.

The argument above makes which one of the following assumptions?

(A) Biotechnology should be directed toward producing plants that do not require artificial fertilizer. - WRONG. Irrelevant.

(B) Fixed nitrogen is currently the only soil nutrient that must be supplied by artificial fertilizer for growing wheat crops. - WRONG. Being the only nutrient is not a necessary assumption.

(C) There are no naturally occurring strains of wheat or other grasses that have Rhizobium bacteria living in their roots. - WRONG. If there are none that have bacteria in their roots then too passage holds. If there are one then too we are not sure whether the nitrogen is supplied. 2nd best choice for me.

(D) Legumes are currently the only crops that produce their own supply of fixed nitrogen. - WRONG. Not a necessary assumption for the passage to be true as it is.

(E) Rhizobium bacteria living in the roots of wheat would produce fixed nitrogen. - CORRECT. If not then passage doesn't hold true as concluded.

Answer E.
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