Space scientists Anna-Lisa Paul, Stephen M. Elardo, and Robert Ferl planted seeds of Arabidopsis thaliana in samples of lunar regolith—the...
GMAT Craft and Structure : (Structure) Questions
Space scientists Anna-Lisa Paul, Stephen M. Elardo, and Robert Ferl planted seeds of Arabidopsis thaliana in samples of lunar regolith—the surface material of the Moon—and, serving as a control group, in terrestrial soil. They found that while all the seeds germinated, the roots of the regolith-grown plants were stunted compared with those in the control group. Moreover, unlike the plants in the control group, the regolith-grown plants exhibited red pigmentation, reduced leaf size, and inhibited growth rates—indicators of stress that were corroborated by postharvest molecular analysis.
Which choice best states the main purpose of the text?
It describes an experiment that addressed an unresolved question about the extent to which lunar regolith resembles terrestrial soils.
It compares two distinct methods of assessing indicators of stress in plants grown in a simulated lunar environment.
It presents evidence in support of the hypothesis that seed germination in lunar habitats is an unattainable goal.
It discusses the findings of a study that evaluated the effects of exposing a plant species to lunar soil conditions.
Step 1: Decode and Map the Passage
Part A: Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| 'Space scientists Anna-Lisa Paul, Stephen M. Elardo, and Robert Ferl planted seeds of Arabidopsis thaliana in samples of lunar regolith—the surface material of the Moon—and, serving as a control group, in terrestrial soil.' |
|
| 'They found that while all the seeds germinated, the roots of the regolith-grown plants were stunted compared with those in the control group.' |
|
| 'Moreover, unlike the plants in the control group, the regolith-grown plants exhibited red pigmentation, reduced leaf size, and inhibited growth rates—indicators of stress that were corroborated by postharvest molecular analysis.' |
|
Part B: Passage Architecture & Core Elements
Main Point: An experiment revealed that while plants can germinate in lunar soil, they show significant stress indicators compared to plants grown in Earth soil.
Argument Flow: The passage establishes the experimental design, then systematically presents the findings—first the basic germination success, then the comparative problems (stunted roots), and finally the comprehensive stress indicators that were scientifically confirmed.
Step 2: Interpret the Question Precisely
What's being asked? The main purpose of the entire text
What type of answer do we need? A statement that captures what the passage is fundamentally trying to accomplish
Any limiting keywords? Content Genre: Sciences, Content Format: Text-only, Question Type: Main Point or Purpose (entire), Language Complexity: Moderate
Step 3: Prethink the Answer
- The passage is fundamentally about scientists conducting an experiment to see what happens when you grow plants in lunar soil instead of Earth soil
- The key elements the correct answer must have:
- It should mention that this discusses an experiment or study
- It should indicate they were testing the effects of lunar soil conditions on plants
- It should capture that they found negative effects (stress indicators)
It describes an experiment that addressed an unresolved question about the extent to which lunar regolith resembles terrestrial soils.
✗ Incorrect
- This suggests the experiment was about comparing how similar lunar and Earth soils are, but the passage focuses on plant responses to lunar soil
It compares two distinct methods of assessing indicators of stress in plants grown in a simulated lunar environment.
✗ Incorrect
- This claims the passage compares two different methods of measuring plant stress, but we only see one approach
It presents evidence in support of the hypothesis that seed germination in lunar habitats is an unattainable goal.
✗ Incorrect
- This says the evidence shows seed germination is 'unattainable' but the passage explicitly states 'all the seeds germinated'
It discusses the findings of a study that evaluated the effects of exposing a plant species to lunar soil conditions.
✓ Correct
- Accurately captures that this discusses 'findings of a study' and correctly identifies that the study 'evaluated the effects of exposing a plant species to lunar soil conditions'