Industrial activity is often assumed to be a threat to wildlife, but that isn't always so. Consider the silver-studded blue...
GMAT Craft and Structure : (Structure) Questions
Industrial activity is often assumed to be a threat to wildlife, but that isn't always so. Consider the silver-studded blue butterfly (Plebejus argus): as forest growth has reduced grasslands in northern Germany, many of these butterflies have left meadow habitats and are now thriving in active limestone quarries. In a survey of multiple active quarries and patches of maintained grassland, an ecologist found silver-studded blue butterflies in \(100\%\) of the quarries but only \(57\%\) of the grassland patches. Moreover, butterfly populations in the quarries were four times larger than those in the meadows.
Which choice best describes the function of the underlined portion in the text as a whole?
It challenges a common assumption about the species under investigation in the research referred to in the text.
It introduces discussion of a specific example that supports the general claim made in the previous sentence.
It suggests that a certain species should be included in additional studies like the one mentioned later in the text.
It provides a definition for an unfamiliar term that is central to the main argument in the text.
Step 1: Decode and Map the Passage
Part A: Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| 'Industrial activity is often assumed to be a threat to wildlife, but that isn't always so.' |
|
| 'Consider the silver-studded blue butterfly (Plebejus argus):' |
|
| 'as forest growth has reduced grasslands in northern Germany, many of these butterflies have left meadow habitats and are now thriving in active limestone quarries.' |
|
| 'In a survey of multiple active quarries and patches of maintained grassland, an ecologist found silver-studded blue butterflies in 100% of the quarries but only 57% of the grassland patches.' |
|
| 'Moreover, butterfly populations in the quarries were four times larger than those in the meadows.' |
|
Part B: Passage Architecture & Core Elements
Main Point: Industrial activity isn't always harmful to wildlife, as demonstrated by silver-studded blue butterflies that are actually thriving in limestone quarries better than in natural grassland habitats.
Argument Flow: The passage opens by challenging the assumption that industry always threatens wildlife. It then introduces a specific butterfly species as an example and provides context about how habitat changes led these butterflies to move from natural meadows to industrial quarries. Finally, it presents concrete research data showing the butterflies are not just surviving but actually doing much better in the industrial sites.
Step 2: Interpret the Question Precisely
What's being asked? The role or purpose this specific sentence serves within the overall structure of the passage.
What type of answer do we need? A description of how this sentence functions - what job it performs in relation to the rest of the text.
Any limiting keywords? We're asked about the function of the underlined portion 'Consider the silver-studded blue butterfly (Plebejus argus):' in the text as a whole.
Step 3: Prethink the Answer
- The underlined sentence comes right after the opening claim that challenges assumptions about industry and wildlife
- The sentence introduces a specific butterfly species that we can examine
- Based on what follows, this butterfly becomes the concrete example that proves the opening claim
- It's the evidence that shows industry isn't always harmful to wildlife
- The right answer should explain that this sentence introduces a specific example that will be used to support or prove the general claim made at the beginning of the passage
It challenges a common assumption about the species under investigation in the research referred to in the text.
✗ Incorrect
- This suggests the sentence challenges an assumption about the butterfly species itself
- But the sentence doesn't challenge any assumption - it simply introduces the species name
- The challenge to assumptions happened in the previous sentence about industry and wildlife in general
It introduces discussion of a specific example that supports the general claim made in the previous sentence.
✓ Correct
- This perfectly captures what we identified in our prethinking
- The previous sentence made a general claim (industry isn't always a threat to wildlife)
- This sentence introduces the specific butterfly that will serve as the supporting example
- The rest of the passage then uses this butterfly to prove that general claim
It suggests that a certain species should be included in additional studies like the one mentioned later in the text.
✗ Incorrect
- This suggests the sentence is making a recommendation about future research
- But the sentence doesn't suggest anything about additional studies
- It's simply introducing an example that supports the current argument
It provides a definition for an unfamiliar term that is central to the main argument in the text.
✗ Incorrect
- While the sentence does provide the scientific name in parentheses, that's not its primary function
- The main job isn't defining a term but introducing an example
- What trap this represents: Students might focus on the parenthetical scientific name and think this is primarily definitional, missing the larger structural purpose of introducing supporting evidence