Chile's Atacama Desert is one of the driest places on Earth. Mary Beth Wilhelm and other astrobiologists search for life,...
GMAT Craft and Structure : (Structure) Questions
Chile's Atacama Desert is one of the driest places on Earth. Mary Beth Wilhelm and other astrobiologists search for life, or its remains, in this harsh place because the desert closely mirrors the extreme environment on Mars. The algae and bacteria found in Atacama's driest regions may offer clues about Martian life. By studying how these and other microorganisms survive such extreme conditions on Earth, Wilhelm's team hopes to determine whether similar life might have existed on Mars and to develop the best tools to look for evidence of it.
Which choice best describes the function of the underlined sentence in the text as a whole?
To contrast the conditions in the Atacama Desert with those on Mars
To explain why many life-forms cannot survive in the Atacama Desert
To indicate why astrobiologists choose to conduct research in the Atacama Desert
To describe certain limitations to conducting scientific study in the Atacama Desert
Step 1: Decode and Map the Passage
Part A: Create Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| 'Chile's Atacama Desert is one of the driest places on Earth.' |
|
| 'Mary Beth Wilhelm and other astrobiologists search for life, or its remains, in this harsh place because the desert closely mirrors the extreme environment on Mars.' |
|
| 'The algae and bacteria found in Atacama's driest regions may offer clues about Martian life.' |
|
| 'By studying how these and other microorganisms survive such extreme conditions on Earth, Wilhelm's team hopes to determine whether similar life might have existed on Mars and to develop the best tools to look for evidence of it.' |
|
Part B: Provide Passage Architecture
Main Point: Scientists study life in Chile's Atacama Desert because its Mars-like conditions can help them understand whether life could exist on Mars and how to search for it.
Argument Flow: The passage establishes the Atacama Desert as an extremely dry place, then explains that scientists research there specifically because it resembles Mars. It describes what they hope to learn from the microorganisms they find and how this research serves both scientific understanding and practical tool development for Mars exploration.
Step 2: Interpret the Question Precisely
What's being asked? The question asks about the function of the underlined sentence within the overall text structure.
What type of answer do we need? We need to identify the role or purpose this specific sentence serves in the passage.
Any limiting keywords? No specific limiting keywords identified.
Step 3: Prethink the Answer
- The underlined sentence connects the extreme setting to the scientists' decision to work there
- It provides the logical bridge between the desert being dry and scientists choosing to research there
- The 'because' clause explains the reasoning: the desert mirrors Mars conditions
To contrast the conditions in the Atacama Desert with those on Mars
✗ Incorrect
- This suggests the sentence shows differences between Atacama and Mars
- The sentence actually emphasizes their similarity with the word 'mirrors'
To explain why many life-forms cannot survive in the Atacama Desert
✗ Incorrect
- This would mean the sentence explains why life struggles in Atacama
- The sentence focuses on why scientists choose to research there, not on biological limitations
To indicate why astrobiologists choose to conduct research in the Atacama Desert
✓ Correct
- This perfectly matches our analysis
- The sentence literally explains why astrobiologists search for life in this location
- The 'because' clause provides the exact rationale: the similarity to Mars conditions
To describe certain limitations to conducting scientific study in the Atacama Desert
✗ Incorrect
- This would suggest the sentence discusses research challenges
- Instead it explains the advantage of researching in Atacama as an asset for Mars-related research