GRE General TestVerbal ReasoningHard
Reading Comprehension: Main Idea: The recent discovery of extremophiles thriving in environments previously thought inhospitable to life—such as hydrothermal vents on the ocean floor and beneath Antarctic ice sheets—has profound implications for astrobiology. These organisms, adapted to extreme temperatures, pressures, and chemical compositions, suggest that life may be far more resilient and widespread in the universe than once imagined. Their existence challenges conventional definitions of habitability and expands the search parameters for extraterrestrial life, shifting focus from Earth-like planets to a broader range of celestial bodies. This paradigm shift underscores the dynamic nature of scientific understanding and the constant need for reevaluation in light of new evidence.
- AHydrothermal vents are the most likely places to find life on other planets.
- BExtremophiles are a newly discovered type of organism.
- CThe discovery of extremophiles broadens the scope of the search for extraterrestrial life.
- DScientists are redefining the term 'life' due to extremophile discoveries.
Show answer & explanationAnswer & explanation
Correct answer: C. The discovery of extremophiles broadens the scope of the search for extraterrestrial life.
The passage consistently emphasizes how extremophiles 'have profound implications for astrobiology,' 'suggest that life may be far more resilient and widespread,' 'expands the search parameters for extraterrestrial life,' and causes a 'paradigm shift.' All these phrases point to the main idea that the discovery changes how we search for life elsewhere.
Why the other options are wrong
- A. The passage mentions hydrothermal vents as an example of where extremophiles are found, but doesn't claim they are the *most likely* places for extraterrestrial life; it's about expanding the search *in general*.
- B. While extremophiles are discussed, the main idea isn't their novelty but their impact on astrobiology.
- D. The passage states their existence 'challenges conventional definitions of habitability,' not necessarily 'redefining the term life' itself.
Reading Comprehension Main Idea
The central point or message the author is trying to convey in a passage.
- Often found in the introduction or conclusion, or summarized by the overall argument.
- Must be broad enough to encompass the entire passage but specific enough to be accurate.
- Requires synthesizing information from across the text rather than isolated details.
Memory trick: Find the trunk of the tree, not just the leaves; it holds the whole thing up.