Question 53·Medium·Text Structure and Purpose
Biologist Carla Ruiz has long argued that urban green roofs can serve as critical habitats for native pollinators. Her latest study focuses on measuring how rooftop vegetation affects bee diversity in downtown Chicago. Ruiz compared bee populations on roofs planted with a single flowering species to those on roofs containing a mix of ten native species. The study’s findings suggest that rooftops with greater plant diversity host significantly more bee species, offering city planners a blueprint for boosting urban biodiversity.
Which choice best describes the primary function of the underlined sentence in the passage?
For SAT questions asking about the function of a sentence, first locate the sentence in the passage’s structure: is it in the introduction, in the middle of an argument, or near the conclusion? Then paraphrase the sentence in simple words and decide if it is giving background, describing a method, presenting evidence, stating a result, or commenting on other research. Finally, match that role to the answer choices and quickly eliminate any that introduce ideas not present in the sentence (like criticism, new topics, or results) or that actually describe what a different nearby sentence is doing. Always let the exact wording and its position in the paragraph guide you, not what sounds sophisticated.
Hints
Check the placement of the bolded sentence
Notice where the bolded sentence appears: it comes after the description of what the study focuses on and before the sentence about the study’s findings. Think about what usually comes between a study’s focus and its findings.
Paraphrase what the bolded sentence literally says
Ignore the answer choices for a moment. Put the bolded sentence into your own words: what exactly is Ruiz doing in that sentence? Is she describing results, methods, background, or a criticism?
Contrast the bolded sentence with the following one
Compare the bolded sentence to the sentence that starts "The study’s findings suggest…" Which sentence is about what the researcher did, and which is about what the researcher found? Use that contrast to eliminate answer choices that confuse these roles.
Eliminate answers that bring in new ideas
Look for answer choices that mention ideas not in the bolded sentence, like criticizing other research, building design, or summarizing results. If the bolded sentence doesn’t do those things, those choices are likely wrong.
Step-by-step Explanation
Identify what the question is asking
The question asks for the primary function of the bolded sentence in the passage. That means you need to explain what role that sentence plays in the author's overall presentation: Is it background, method, results, criticism, or something else?
Paraphrase the bolded sentence in your own words
The bolded sentence says: "Ruiz compared bee populations on roofs planted with a single flowering species to those on roofs containing a mix of ten native species."
In your own words: Ruiz is comparing bee populations on two different kinds of green roofs—one type with just one flowering plant species, and another type with a mix of ten native species. This is a description of how the study was set up.
Look at the surrounding context
Read the sentences before and after the bolded sentence:
- Before: The passage introduces Ruiz’s argument that green roofs can help pollinators and says her latest study focuses on measuring how rooftop vegetation affects bee diversity.
- Bolded: It tells exactly what she compared to measure that effect.
- After: "The study’s findings suggest that rooftops with greater plant diversity host significantly more bee species…" — this sentence gives the results/conclusions that come from that comparison.
So the bolded sentence connects the study’s focus (effect of vegetation on bees) to its conclusions by telling you what was compared in the experiment.
Test each answer choice against the sentence’s actual role
Now match that understanding against each option:
- One choice claims the sentence is criticizing earlier research by pointing out a flaw.
- One claims it’s describing the buildings themselves (architectural characteristics).
- One claims it’s summarizing the study’s key findings.
- One claims it’s stating the specific comparison that the later conclusions depend on.
The bolded sentence does not criticize past research, describe building structure, or state results. It clearly describes the two groups being compared in the experiment, which is the foundation for the conclusions in the next sentence.
Therefore, the correct answer is: It specifies the experimental comparison that forms the basis for the study’s subsequent conclusions.