Question 31·Easy·Text Structure and Purpose
A team of biologists recently attached lightweight tracking devices to monarch butterflies to follow their lengthy migration from Canada to Mexico. The data collected reveal new stopover points and shed light on how changing weather patterns influence the insects’ routes. Researchers say these findings will help conservationists protect critical habitats along the journey.
Which choice best states the main purpose of the text?
For main purpose questions, first cover the choices and quickly summarize the passage in your own words using the first and last sentences, plus any repeated ideas. Then check each option against this summary: the correct choice will match what the entire passage is doing, while wrong choices usually (1) focus on a detail mentioned only once, (2) introduce ideas not in the text, or (3) change the focus (for example, from reporting research to describing appearance or giving opinions). Eliminate any option that doesn’t fit the whole passage, not just one part of it.
Hints
Look at the big picture, not small details
Before checking the answer choices, try to say in one short sentence what the whole passage is doing. Focus on the overall action and purpose, not individual words like “Canada” or “technology.”
Use the first and last sentences
Reread the first and last sentences: what are the biologists doing, and why do the researchers say it matters? That often reveals the main purpose.
Test whether each choice fits the entire passage
For each answer choice, ask: does every sentence in the passage support this idea, or is the choice focusing on something that’s barely mentioned—or not mentioned at all?
Step-by-step Explanation
Identify what the passage is mostly about
Look at the key actions and subjects in the passage: biologists attach tracking devices to monarch butterflies, follow their migration from Canada to Mexico, collect data on stopover points and weather effects, and say how the findings will help conservationists. All of this centers on a scientific investigation involving monarch migration and its results.
Restate the main purpose in your own words
In your own words, you could summarize the passage as: it tells us about a research project where scientists track monarch butterflies on their long migration and explains what they learned and why it matters for conservation. This is an informational, science-report style purpose.
Eliminate choices that don’t match this purpose
Now compare each option to your summary of the passage’s purpose:
- One option focuses on the beauty of wing patterns, but the passage never mentions how the butterflies look.
- Another option talks about new technology improving agricultural yields, but the passage doesn’t mention crops or farming at all.
- A third option focuses on describing the climate of Canada and Mexico, but the passage only mentions those places as start and end points of the migration, not to describe their climate. Only one remaining choice matches the idea of describing a research project about monarch migration and its findings.
Match the remaining choice to the passage
The only option that fits the passage’s overall focus—explaining what scientists did to follow monarch butterflies’ long journey, what their data showed, and how it will help conservation—is “To report on a study tracking monarch butterfly migration.”