When invasive zebra mussels were introduced to the Great Lakes ecosystem in the 1980s, they consumed vast amounts of phytoplankton...
GMAT Expression of Ideas : (Expression) Questions
When invasive zebra mussels were introduced to the Great Lakes ecosystem in the 1980s, they consumed vast amounts of phytoplankton that native fish species relied upon for food. _____ native fish populations began declining rapidly, and several species faced near-extinction in affected areas.
Which choice completes the text with the most logical transition?
As a result,
On the other hand,
For instance,
Nevertheless,
I'll solve this step-by-step, following the structured process for analyzing SAT passage-based questions.
Step 1: Decode and Map the Passage
Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| "When invasive zebra mussels were introduced to the Great Lakes ecosystem in the 1980s, they consumed vast amounts of phytoplankton that native fish species relied upon for food." |
|
| [MISSING TRANSITION] |
|
| "native fish populations began declining rapidly, and several species faced near-extinction in affected areas." |
|
Passage Architecture & Core Elements
Main Point: The introduction of invasive zebra mussels led to severe consequences for native fish populations by disrupting their food supply.
Argument Flow: The passage presents a classic cause-and-effect scenario. The missing transition needs to connect the cause (zebra mussels consuming food) to the effect (fish population decline).
Step 2: Interpret the Question Precisely
This is a fill-in-the-blank question asking us to choose the best logical connector. The answer must create the right relationship between what comes before and after the blank.
Step 3: Prethink the Answer
- We need a transition that shows the logical relationship between zebra mussels eating the fish's food and fish populations declining
- This is clearly a cause-and-effect relationship
- The transition should signal that what follows is a direct consequence of what came before
As a result,
✓ Correct
- "As a result" perfectly signals a cause-and-effect relationship
- It connects the cause (zebra mussels eating fish food) to the effect (fish population decline)
- Matches our prethinking about needing a consequence indicator
On the other hand,
✗ Incorrect
- "On the other hand" signals contrast or opposition between ideas
- There's no contrast here - the fish decline directly follows from the food disruption
For instance,
✗ Incorrect
- "For instance" introduces a specific example of a broader concept
- The fish decline isn't an example - it's the direct consequence of the mussel invasion
Nevertheless,
✗ Incorrect
- "Nevertheless" suggests something happens despite what came before
- The fish decline happened because of the food disruption, not in spite of it