Rhizobium Bacteria Living In The Roots Of Bean Plants Or Other Legumes GMAT Critical Reasoning

Question: 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.
(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.

“Rhizobium bacteria living in the roots of bean plants or other legumes” - is a critical thinking GMAT question. In order to respond to the question, a candidate may decide to present an illogical argument or look for evidence that would refute it. A candidate's capacity for logic and analysis is evaluated on the GMAT critical reasoning exam. Candidates must point out the argument's benefits and drawbacks as well as its logical errors with regard to this subject. Ten to thirteen questions on critical reasoning are included in the CR section of the 36 GMAT verbal questions.

Answer: (E)
Explanation:

One of the essential plant nutrients, fixed nitrogen, is produced by Rhizobium bacteria in the roots of bean plants and other legumes. For non-legume crops, like wheat, this nutrient must typically be supplied through the use of nitrogen-based fertilizers. Therefore, the use of synthetic fertilizers will be lessened if biotechnology is successful in creating wheat strains whose roots will support rhizobium bacteria.

Let us analyze each option separately to find the correct answer which will be an assumption made by the argument.

Option A : Incorrect

According to this option, biotechnology should be used to create plants that don't need artificial fertilizer. The conclusion is unaffected by this in any way. The conclusion deals with reducing the need for artificial fertilizers due to a supply of nitrogen through the use of biotechnology. Therefore this option is rejected.

Option B : Incorrect

According to this option, the only soil nutrient currently required by wheat crops for growth is fixed nitrogen. The absence of other soil nutrients would negate the importance of nitrogen. It does not invalidate the conclusion because biotechnology could still be used to reduce demand. Therefore this option is rejected.

Option C : Incorrect

This option states that there are no wheat or other grass varieties that naturally contain Rhizobium bacteria in their roots. Biotechnology can still work its magic and provide more fixed nitrogen even if there are some strains. Therefore this option is rejected.

Option D : Incorrect

This option states that at the moment, only crops that produce their own supply of fixed nitrogen are legumes. This has absolutely no bearing on the conclusion. Therefore this option is rejected.

Option E : Correct

According to this option, Rhizobium bacteria that inhabit wheat roots would produce fixed nitrogen. The conclusion would be ruined if this were denied. Fertilizer use won't decrease if Rhizobium bacteria do not produce fixed nitrogen after being transplanted into wheat crops. Therefore this option is the right choice.

Suggested GMAT Critical Reasoning Samples

• Compact fluorescent light (CFL) bulbs are growing in market share as a replacement for the standard incandescent light bulb GMAT Critical Reasoning
• When a caterpillar emerges from the egg on a tree branch, it immediately climbs upward until it finds a leaf bud to eat GMAT Critical Reasoning
• The citizens of Country 777 pay very high prices for Internet connections GMAT Critical Reasoning
• It is crucially important to farmers that the herbicides they use to control weeds not damage their crops GMAT Critical Reasoning
• Civic Leader: The high cancer rate among our citizens is the result of hazardous material produced at your plant GMAT Critical Reasoning
• Paleontologists hypothesize that modern birds evolved from the family of dinosaurs that included Tyrannosaurus rex GMAT Critical Reasoning
• Whether one is buying men’s or women’s clothing, it pays to consider fashion trends GMAT Critical Reasoning
• Some anthropologists study modern-day societies of foragers in an effort to learn about our ancient ancestors who were also foragers GMAT Critical Reasoning
• Using oil-based paints to paint walls or furniture requires the use of turpentine and each coat takes a long time to dry GMAT Critical Reasoning
• The Elk City garbage dumps are so full that Elk City has been forced to pay a large sum to Caribou City GMAT Critical Reasoning
• Since Java coffee shop began advertising on the local radio station 3 months ago, its business volume has increased by 15% GMAT Critical Reasoning
• During ancient times, the floknee was a common animal in the Wekerlee district long before the arrival of humans to the area GMAT Critical Reasoning
• In order to increase profits during a prolonged slowdown in sales, the largest manufacturers of automobiles in the United States have instituted record-setting price increases on all their models GMAT Critical Reasoning
• A major film studio announced the release date of a movie based on a novel that was a bestseller GMAT Critical Reasoning
• Roland: The alarming fact is that 90 percent of the people in this country now report that they know someone who is unemployed GMAT Critical Reasoning
• For the first time since influenza vaccines became popular, the demand for the vaccine exceeds the supply in our state GMAT Critical Reasoning
• Many airlines have been pushing the federal government for assurances of greater security in case of terrorist attacks onboard flights GMAT Critical Reasoning
• The increased concentration of salt in the bay, which is the result of the recent drought and high temperatures, will cause many fish to die GMAT Critical Reasoning
• The sport of tennis develops muscular strength, sharpens coordination, and provides good cardiovascular exercise GMAT Critical Reasoning
• TOMMY: That telephone always rings when I am in the shower and can’t hear it GMAT Critical Reasoning