The greatest chance for the existence of extraterrestrial life is on

Question

The greatest chance for the existence of extraterrestrial life is on a planet beyond our solar system. The Milky Way galaxy alone contains 100 billion other suns, many of which could be accompanied by planets similar enough to Earth to make them suitable abodes of life.

The statement presupposes which of the following?

A. Living creatures on another planet would probably have the same appearance as those on Earth.

B. Life cannot exist on other planets in our solar system.

C. If the appropriate physical conditions exist, life is an inevitable consequence.

D. More than one of the suns in the galaxy is accompanied by an Earth-like planet.

E. It is likely that life on another planet would require conditions similar to those on Earth.

Bunuel · Accepted Answer

OFFICIAL EXPLANATION

In stating that planets may exist that are similar enough to Earth to make them suitable for supporting life, the author implicitly rules out planets dissimilar to Earth as likely to support life. The assumption underlying the statement is that life on another planet is likely to require conditions similar to those on Earth.  Therefore, E is the correct answer.

A is not correct. The statement presupposes nothing about the appearance of extraterrestrial life. B is incorrect. The statement implies that it is relatively unlikely that life exists on other planets in our solar system, but it makes no presupposition absolutely ruling out the possibility that such life exists. The answer choice of C is incorrect. Although the statement suggests that there is the greatest chance for life when physical conditions are appropriate, it leaves open the possibility that no life will exist even with appropriate conditions. D is also incorrect. The statement says that it is possible that more than one of the suns in the galaxy is accompanied by an Earth-like planet, but it does not presuppose that there are actually any such suns.

abelka · Answer

A. Living creatures on another planet would probably have the same appearance as those on Earth. -   INCORRECT

B. Life cannot exist on other planets in our solar system. -   INCORRECT

C. If the appropriate physical conditions exist, life is an inevitable consequence. -   INCORRECT

D. More than one of the suns in the galaxy is accompanied by an Earth-like planet. -   INCORRECT

E. It is likely that life on another planet would require conditions similar to those on Earth  Correct

manassingari · Answer

but if option B is negated then the conclusion will breakdown , since it will say that life can exist 
in our solar system then why need to go to any other solar system ?

RohitSaluja · Answer

Hi  VeritasKarishma   GMATNinja   EducationAisle . I am confused between option D and E, the conclusion of the argument is "The  greatest chance  for the existence of extraterrestrial life is on a planet beyond our solar system" and the author support this by stating that 100 billions of other sun could have plantes similar to earth.

If we don't have more than one sun in the galaxy accompanied by Earth like planet, then how can the conclusion still stands "the greatest chance". I see how E also impacts the conclusion, but I am not able to eliminate D

KarishmaB · Answer

Milky way galaxy alone contains 100 billion other suns, many of which could be accompanied by planets similar enough to Earth to make them suitable abodes of life.

Conclusion: The greatest chance for the existence of extraterrestrial life is on a planet beyond our solar system.

The argument says that the greatest chance of extraterrestrial life is beyond our solar system (not in our solar system). Presumably, the other planets of our solar system are not like Earth. In milky way itself, there are 100 billion other suns with planets. Many of these planets could be similar to Earth to make them suitable for life.

What is the assumption? That you need a planet similar to Earth to support life. Our solar system doesn't work because other planets are not similar to Earth. But there are billions of other Suns and planets and many of them could be similar to Earth.

A. Living creatures on another planet would probably have the same appearance as those on Earth.
Not assumed anything about appearance of creatures.

B. Life cannot exist on other planets in our solar system.
Doesn't assume. Just talks about possibilities.

C. If the appropriate physical conditions exist, life is an inevitable consequence. 
Doesn't say it is inevitable.

RohitSaluja

D. More than one of the suns in the galaxy is accompanied by an Earth-like planet.
It doesn't assume this. The premise gives that it is likely that many suns are accompanied by Earth like planets. So we need to take it as true. An assumption is something which is not given.

E. It is likely that life on another planet would require conditions similar to those on Earth.
Correct. The whole argument depends on this. Even though it is never mentioned that life requires Earth like conditions but the argument assume it to say that extraterrestrial life is likely to exist beyond our solar system.

Answer (E)

The greatest chance for the existence of extraterrestrial life is on

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The greatest chance for the existence of extraterrestrial life is on

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