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Question

The field of exobiology seeks to understand the origin, evolution, and distribution of life in the universe. Exobiology as a discipline emerged shortly after a 1953 experiment conducted at the University of Chicago that used electricity and simple gases to produce amino acids, the building blocks of proteins and, therefore, organic life as we know it. The experiment was conducted by a biology graduate student, Stephen Miller, in the lab of Harold Urey, a scientist who was already well-known for his theories on the composition of the early earth’s atmosphere. Miller and Urey put three gases believed to have been present in the early atmosphere – methane, ammonia, and hydrogen – into a closed system with an “ocean” of water at the bottom and ran electricity through the gases to simulate the lightening storms believed common on the early earth. At the end of a week, the scientists observed that basic organic compounds, including amino acids, had formed and dissolved in the water, where some of them had even combined to form more complex, though still non-living, substances.
 
Drawing on established scientific methodologies, exobiology synthesizes data and theories from various disciplines such as biology, chemistry, and physics to explore life's potential beyond our planet. Though parts of the Miller-Urey experiment have been thrown into question by more recent discoveries, exobiology remains a small, close-knit field of dedicated scientists with backgrounds in areas as diverse as biology, chemistry and physics. Much of the current research supported by NASA, the American space agency, focuses on four major areas. The first two speculate about the evolution of compounds necessary to organic life, whether that be the development in space of “biogenic,” or life-generating compounds, or the planetary evolution of compounds that are considered “prebiotic,” or pre-living. A third area seeks to trace steps of transformation from organic compounds to simple forms of life, and a fourth studies the evolution from simple organisms to the complex and diverse forms of life found on earth today. Investigations in all four areas involve a mixture of approaches: observation of simple life-forms, such as bacteria and viruses; examination of materials from space, such as asteroids, which seem to contain evidence of life; speculation based on data gathered from telescopes and space probes; and experimentation.  1. The primary purpose of the passage is to

(a) speculate about the origin of life in the universe
(b) overturn an outdated, though popular, scientific theory
(c) contrast two approaches to the study of the origin of life
(d) trace the chronological development and historical milestones of a field of study
(e) examine the foundations and scientific objectives of exobiology
 E

2. 
Based on information in the passage, which of the following can be concluded about organic compounds?
 
Organic compounds .

(a) are not living, but are the building blocks of life
(b) were discovered in 1953, as part of a famous experiment
(c) can be formed more quickly than inorganic compounds
(d) combine only in the presence of electricity
(e) contain gases such as ammonia, methane, and hydrogen
 A

3. The author refers to an “ocean” most likely in order to

(a) suggest that gases are not sufficient to create organic compounds.
(b) emphasize that the experiment sought to replicate conditions of early earth.
(c) shed light on the mindset of scientists conducting the experiment.
(d) disprove the theory that early earth’s oceans were of a substance other than water.
(e) provide an example of a substance common to early earth.
 B

Bunuel · Answer

Main Idea questions require a true statement about information provided in the passage as a whole. The first sentence of the paragraph contains a definition of exobiology, and the remainder of the passage further supports this definition by discussing the origins of the field (paragraph 1) and its goals (paragraph 2).   This is a goal of exobiology itself, not this passage. 
 The passage does not suggest a single theory; therefore, a theory can not be overthrown. 
 Two approaches are neither introduced nor contrasted in the passage. 
 This is the main idea only of paragraph 1. 
 This option correctly summarizes information contained in both paragraphs of the passage.     The phrase  based on information in the passage  in the question stem reveals that the answer to this question can be found by reviewing what is stated explicitly in the passage. This line states that amino acids are  the building blocks of proteins and, therefore, organic life as we know it . Combining this information with that provided in this line, which further emphasizes that amino acids are  organic compounds , it can be concluded that organic compounds  are the building blocks of life  even though they are not living.   This information can by found by combining relevant sentences in the first paragraph. 
 The paragraph states that the experiment was conducted in 1953, but not that organic compounds were discovered then. 
 This claim is not made in the passage. 
 The passage does not make this claim. 
 Though this is true of the organic compounds discussed in the first paragraph, the passage does not make this claim for  all  organic compounds.     The answer to this question depends on drawing a conclusion based on information stated in the passage. To begin, review the text where the  ocean  is mentioned. The reference occurs within the context of Miller and Urey’s experiment, in which they attempted to re-create conditions present on the early earth to test whether organic compounds could be formed. It can be concluded, then, that the word  ocean  is meant to be included in the list of conditions replicating the situation of the early earth.   Though water and electricity are also used to create organic compounds in this experiment, this has no bearing on the fact that the author chose the word  ocean . 
 This option correctly recognizes the placement of the word  ocean  within the context of an experiment that sought to replicate conditions present on the early earth. 
 The word  ocean  is in itself irrelevant to the mindset of Miller and Urey. 
 This theory is neither mentioned nor refuted in the passage. 
 This option is close to being correct, but does not correctly evaluate the word  ocean  in the context of an experiment which sought to  recreate  certain conditions.

Rickooreo · Answer

bb   sayantanc2k   Bunuel   Sajjad1994

For option E - discuss the origins and goals of  a branch of science 
How was it inferred that this is a branch of science, because scientists were involved?

sayan640 · Answer

bb   KarishmaB  , I also have the similar doubt . Where was it mentioned that exobiology is a branch of science ? Request you to pitch in.

bb · Answer

You are right. It was not explicitly mentioned. There was only some hints that were debatable. I have revised the options.

BongBideshini · Answer

Q1.
  bb , I'm unable to understand that the passage's primary purpose is to "examine." I think the author has merely "presented" exobiology instead of "examining" it. 
 Help me out !

SanketPatil · Answer

I have the same doubt, how can we conclude that they are examining, when it merely states the fact about the programs

bhanu29 · Answer

Oxford dictionary defines examine as    to consider or study an idea, a subject, etc. very carefully   
  
'Examine' doesn't mean 'critically analyse' or 'argue'; it simply means 'study', which could be as an explanation about a topic in an organised way (kind of a survey/review of what it is).

The passage does exactly this: it explains what exactly exobiology is and talks about its origin and some basics about how it is studied.

You can see that the author isn't merely presenting facts, but he is explaining it in an organised, neutral manner with his own thoughts.

Besides, other options don't even come close to the primary purpose; therefore, E is the correct answer.

Hope that helps!!

Vivek1707 · Answer

I did not quite understand the question. The first part of the answer choice is debatable!

The passage says

" At the end of a week, the scientists observed that basic organic compounds, including amino acids, had formed and dissolved in the water, where some of them had even combined to form more complex, though still non-living, substances."

This implies that "some" organic compounds are non living subtances

But answer choices says A says

"Organic compounds ARE not living" but are the building blocks of life

i.e the answer choice implies that organic compounds in GENERAL are NON LIVING.

From SOME we cannot infer that organic compounds in GENERAL are non living subtances!!!

Maybe if the answer choice included words implying some that would be 100% inferrable.

bhanu29 · Answer

I think this makes it pretty clear that the first sub sentence is also non-living substance, as a subset of those organic compounds formed more complex STILL non-living substances.
 
Based on the passage A is the only inferable conditions and I think no where it's mentioned "some" organic compounds are non living subtances, implied meaning is the orgainc compounds. are non living substances.
 
Based on the passage A is the only choice that is logically inferable from the passage.
 
Hope that helps!
- B

Vivek1707 · Answer

Hi  bhanu29

Thank you for your response.

I dont dispute the answer. I can understand why that other answers are wrong, my point is the that wording in answer A is not something that can be inferrred with 100% certainity. The answers to all inference questions in official GMAT RC are 100% inferrable without any ambiguity.

Here if you note that the question says " Based on information in the passage, which of the following can be concluded about organic compounds? Organic compounds."

This implies that the question is not just asking about organic compounds in the experiment in the passage. Its asking about organic compounds in general.

From the text in the passage, we cannot infer that organic compounds in general are non living. Even with the use of the word 'still'. It doesnt help.

To give you a parellel example if I say "m etal parts were assembled into complex structures, though still not functional cars"

Can I infer that metal parts cannot be used in functional cars? no I can only say that the metal parts in question were not used in functional cars.

Please let me know if I am thinking in the right direction.

bhanu29 · Answer

Your logic that “some does not equal all” is valid, but in GMAT RC the passage consistently treats organic compounds as non-living, reinforced by the phrase “still non-living” even after increased complexity, and since no exceptions are given it is safe to generalize, so (A) is the best answer even if it is not perfectly airtight in strict formal logic.

Hope that helps!!

- B

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