Because of the proximity and likeness of Mars to Earth, scientists hav

Question

Because of the proximity and likeness of Mars to Earth, scientists have long speculated about the possibility of life on Mars. Roughly three centuries ago, astronomers observed Martian polar ice caps, and later scientists discovered other similarities to Earth, including length of day and axial tilt. But in 1965, photos taken by the Mariner 4 probe revealed a Mars without rivers, oceans, or signs of life. Moreover, in the 1990s, it was discovered that unlike Earth, Mars no longer possessed a substantial global magnetic field, allowing celestial radiation to reach the planet’s surface and solar wind to eliminate much of Mars’s atmosphere over the course of several billion years.

More recent probes have investigated whether there was once liquid water on Mars. Some scientists believe that the presence of certain geological landforms definitively resolves this question. Others posit that wind erosion or carbon dioxide oceans may be responsible for these formations. Mars rovers Opportunity and Spirit, which landed on Mars in 2004, have both discovered geological evidence of past water activity. These findings substantially bolster claims that there was once life on Mars.    1 
 1. The author’s stance on the possibility of life on Mars can best be described as

(A) optimistic
(B) disinterested
(C) skeptical
(D) simplistic
(E) cynical

2  
 2. The passage is primarily concerned with which of the following?

(A) Disproving a widely accepted theory
(B) Initiating a debate about the possibility of life on Mars
(C) Presenting evidence in support of a controversial claim
(D) Describing the various discoveries made concerning the possibility of life on Mars
(E) Detailing the findings of the Mars rovers Opportunity and Spirit

3  
 3. Each of the following discoveries is mentioned in the passage EXCEPT

(A) wind erosion and carbon dioxide oceans are responsible for certain geological landforms on Mars
(B) Mars does not have a substantial global magnetic field
(C) Some water activity existed on Mars at some point in the past
(D) the length of day on Mars is similar to that on Earth
(E) the axial tilt of Mars is similar to that of Earth

4  
 4. In the first paragraph, the author most likely mentions the discovery of polar ice caps to suggest that

(A) until recently Mars’s polar ice caps were thought to consist largely of carbon dioxide
(B) Martian polar ice caps are made almost entirely of water ice
(C) Mars has multiple similarities to Earth, including the existence of polar ice caps
(D) Mars has only a small fraction of the carbon dioxide found on Earth and Venus
(E) conditions on the planet Mars were once very different than they are at present

5  
 5. Each of the following can be inferred from the passage EXCEPT

(A) the presence of certain geological landforms is not definitive proof that there was once life on Mars
(B) similarities to Earth bolster the idea that a planet might be or have been capable of supporting life
(C) the absence of a substantial global magnetic field on Mars suggests that it would be difficult to sustain life on Mars
(D) the presence of water activity on Mars is related to the possibility of life on Mars
(E) the claim that there was once water on Mars has only marginal support from recent discoveries

6  
 6. It can be inferred from the passage that which of the following characteristics of a planet would imply that it might support life?

Indicate all that apply.

A. A significant global magnetic field
B. Evidence of liquid carbon dioxide on the planet’s surface
C. The average daily level of sunlight reaching the planet’s surface

7  
 7. Select the sentence in the passage that provides the best evidence that, at the given time, life did not exist on Mars.    
  "But in 1965, photos taken by the Mariner 4 probe revealed a Mars without rivers, oceans, or signs of life"

Sajjad1994 · Answer

OE

1. The author’s stance on the possibility of life on Mars can best be described as

This passage is concerned with the possibility of life on Mars. It details the various discoveries that have been made over centuries. The passage can best be described as factual and unbiased. When considering a tone question such as this, look for instances in which the author’s opinion is revealed. You should also remember to be wary of extreme words in the answer choices.

A)  The author is neither optimistic nor pessimistic about the possibility of life on Mars.

B)  CORRECT.   Note that the primary meaning of disinterested is “impartial” or “neutral,” which accurately describes the tone of the argument.

C)  There is no indication that the author of the passage is skeptical. The passage simply puts forth facts and does not offer an opinion one way or the other.

D)  The author considers several different factors in the determination of life on Mars. The author’s stance could not appropriately be described as simplistic.

E)  Again, the author is objective in tone and could not accurately be characterized as cynical.

Answer: B

Sajjad1994 · Answer

OE

2. The passage is primarily concerned with which of the following?

This passage is primarily concerned with the possibility of life on Mars. The two paragraphs discuss various discoveries that have been made over the past few centuries. The passage concludes that recent findings substantiate claims that there was once life on Mars. However, scientists are still not certain. In determining the purpose or main idea of the passage, you should avoid extreme words and be able to defend every word. 
 
 A)  This passage does not set out to disprove the theory that there is life on Mars. It is also too extreme to suggest that this is a “widely accepted theory.”

B)  This answer choice is tempting because it is relatively neutral. However, the passage does not seek to initiate a debate; it is more concerned with documenting findings that pertain to life on Mars. In other words, the passage presents the findings that frame a debate; it doesn’t initiate the debate itself.

C)  The passage presents evidence in support of and against the possibility of life on Mars. It is too limited to suggest that the passage is primarily concerned with presenting evidence “in support of” life on Mars.

D) CORRECT.   This answer choice avoids extreme words and best summarizes the purpose of the passage.

E)  This answer choice is too specific. The passage does mention the Mars rovers Opportunity and Spirit, but it is inaccurate to suggest that the passage is primarily concerned with these two rovers. 
 
  Answer: D

Sajjad1994 · Answer

OE

3. Each of the following discoveries is mentioned in the passage EXCEPT

To address this Specific question, point out specific evidence in the text to defend your answer choice. The passage discusses several discoveries; to answer this question, find which of the answer choices is not a discovery specifically mentioned in the passage.

A) CORRECT.   The passage does make mention of wind erosion and carbon dioxide oceans, but the author states that these are other possible explanations for certain geological landforms on Mars. Wind erosion and carbon dioxide oceans are possible causes of the geological landforms rather than “discoveries.” 
 
 B)  At the end of the first paragraph, the passage states that “in the 1990s, it was discovered that, unlike Earth, Mars no longer possessed a substantial global magnetic field.”

C)  In the second paragraph, the author indicates that two rovers “both discovered geological evidence of past water activity.”

D)  Certain similarities Mars has to Earth were discovered sometime between three centuries ago and 1965, including the length of day, as noted in the second sentence of the first paragraph.

E)  Certain similarities Mars has to Earth were discovered sometime between three centuries ago and 1965, including the axial tilt of Mars being similar to that of the Earth, as noted in the second sentence of the first paragraph. 
 
  Answer: A

Sajjad1994 · Answer

4. In the first paragraph, the author most likely mentions the discovery of polar ice caps to suggest that

This is a Specific question that refers back to the second sentence in the first paragraph. The best approach is to reread this sentence and determine, using surrounding sentences, what the author’s purpose is in mentioning Mars’s polar ice caps. If you read the second part of the sentence, “later scientists discovered other similarities to Earth, including length of day and axial tilt,” you notice that polar ice caps are introduced as an example of the similarity of Mars to Earth (note the use of the word other). 
 
 A)  The passage does not mention the content of the polar ice caps, just that they were observed.

B)  Again, you do not know, from the passage, the composition of Mars’s polar ice caps.

C) CORRECT.   As stated above, polar ice caps are introduced as one of several similarities of Mars to Earth.

D)  The passage does not indicate the carbon dioxide content of Mars or Earth. It also does not mention Venus.

E)  While you know from the rest of the passage that conditions on Mars were probably different from what they are now, the author does not mention polar ice caps in order to indicate this. 
 
  Answer: C

Sajjad1994 · Answer

OE

5. Each of the following can be inferred from the passage EXCEPT

A question that asks for an inference from the passage is a Specific question; it is helpful to find evidence for any inference in the text. Make sure each inference can be defended by going back to the text and does not go far beyond the language in the passage.

A)  In the second paragraph, the author states that while the presence of geological landforms may indicate the presence of water, it is also possible that these landforms were caused by wind erosion or carbon dioxide oceans.

B) The first paragraph describes three similarities between Mars and Earth (polar ice caps, length of day, and axial tilt). The passage then contrasts that evidence: “But” later photos showed a planet “without rivers, oceans, or signs of life.” If this later evidence showed no signs of life, in contrast to earlier evidence showing similarities with Earth, then the similarities must support the possibility of life on Mars.

C)  In the second paragraph, the absence of a substantial global magnetic field is presented as evidence of the lack of life on Mars. Again, note that this answer choice avoids extreme words by using the word suggests.

D)  The first sentence in the second paragraph states that “more recent probes have investigated whether there was once liquid water on Mars.” Given this purpose, it is clear that the existence of water is important in order to establish whether or not there was life on Mars.

E) CORRECT.   According to the second paragraph, the “Mars rovers Opportunity and Spirit ... have both discovered geological evidence of past water activity.” As made clear by the subsequent sentence that “these findings substantially bolster claims,” the evidence supporting the claim that there was once water on Mars is substantial. Thus, the passage contradicts the statement that this claim is supported by only marginal evidence. 
 
  Answer: E

Sajjad1994 · Answer

OE

6. It can be inferred from the passage that which of the following characteristics of a planet would imply that it might support life?

Most of the passage is about what aspects of Mars might or might not imply that it once supported life. Seek out direct language in the passage to prove or disprove each possible answer choice.

A. CORRECT.    The passage says that “Mars no longer possessed   a substantial global magnetic field,” which led to the disappearance of Mars’s atmosphere. This dissimilarity with   Earth is used in the passage as evidence against life on Mars.

B.  The passage mentions “carbon dioxide oceans” as a possible   cause for certain geological formations. Another possible (and   contrasting) cause is liquid water. Since water activity is   associated with possible life, and carbon dioxide oceans are   mentioned in contrast, carbon dioxide is probably not evidence of   life.

C.  While your general knowledge of the importance of the sun   might make it reasonable to assume that the sun would be   important on other planets as well, the passage does not discuss   this particular issue. The passage does mention “length of day” as   a similarity between Mars and the Earth, but length of day does   not necessarily mean hours of daylight. A day can also refer to   the length of time it takes a planet to rotate on its own axis.

Answer: B

Sajjad1994 · Answer

OE

7. Select the sentence in the passage that provides the best evidence that, at the given time, life did not exist on Mars.

This Select-in-Passage question asks for evidence that there was not life on Mars at the time that evidence was collected.
 
 The correct answer probably will not be found in the second paragraph, which mostly provides evidence that there was life on Mars at one point.   In the first paragraph, the third sentence says that in 1965,   photos “revealed a Mars without rivers, oceans, or signs of life,”   providing evidence that life did not exist at that time. The next sentence   indicates that the lack of a magnetic field caused some negative   consequences incompatible with life. However, this sentence says that   there is no longer such a magnetic field, indicating that the field did once   exist.

The correct sentence is  “But in 1965, photos taken by the Mariner 4 probe revealed a Mars without rivers, oceans, or signs of life"

Because of the proximity and likeness of Mars to Earth, scientists hav

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards