Question 62·Medium·Central Ideas and Details
The following text is adapted from marine biologist Clara Jensen’s 1924 field journal. In this entry, she records her observations while studying tide pools along the coast at dawn.
The pools have shrunk with the retreating tide, becoming glassy pockets that cradle entire microcosms. I crouch beside one no larger than a serving bowl and watch anemones furl their tentacles like closing fists, safeguarding the nutrients they gathered overnight. Tiny crabs scuttle beneath ribbons of sea lettuce, vanishing the instant my shadow crosses their world. What strikes me most is not the novelty of each creature but the choreography they perform together: the anemone’s discarded waste feeds the algae, the algae’s oxygen nourishes the hermit crab, and the crab’s constant foraging keeps the pool clear of debris. In this confined basin, life is orchestrated with an elegance that rivals any grand ocean vista. I had come expecting to catalogue species; instead, I find myself cataloguing relationships, the invisible threads that bind one life to the next.
Which choice best states the main idea of the text?
For main-idea questions, read the whole passage but rely most on the beginning and ending, plus any sentences where the author directly states what “strikes” them or what they “realize” or “find.” After you briefly summarize that core idea in your own words, eliminate answer choices that: (1) focus on a single detail, (2) introduce new information not in the passage, or (3) contradict the tone. Choose the option that best matches your summary of the passage as a whole, not just one interesting line.
Hints
Find the narrator’s own statement of what matters most
Look for where the narrator says what “strikes” her most or what she finds herself focusing on by the end of the passage.
Distinguish details from the main point
Some sentences describe specific behaviors (like how certain animals react to movement). Others explain why those behaviors matter overall. Ask yourself which idea seems to organize the whole description.
Use the last sentence as a clue
Read the final sentence starting with “I had come expecting to catalogue species…” and think: what does the narrator end up paying attention to instead of individual species?
Match the general idea, not one small moment
Eliminate any answer that focuses on a single detail from one part of the passage rather than on the overall emphasis of the description.
Step-by-step Explanation
Locate the parts that state the author’s focus
First, read the whole passage, but pay special attention to sentences where the narrator directly comments on what stands out to her. In this passage, the key parts are:
- “What strikes me most is not the novelty of each creature but the choreography they perform together…”
- “I had come expecting to catalogue species; instead, I find myself cataloguing relationships…”
These sentences usually reveal the main idea more clearly than descriptive details do.
Summarize that focus in your own words
Look closely at how the narrator describes the tide pool:
- She explains how anemones, algae, and hermit crabs are connected: one’s waste feeds another, oxygen supports another, and the crab’s foraging keeps the pool clean.
- She calls it “choreography” and “life…orchestrated with an elegance,” and talks about “the invisible threads that bind one life to the next.”
Together, these phrases show that her main interest is how the different organisms are linked and affect one another, not just what each one is like on its own.
Check each answer against that main focus
Now compare your summary to the choices:
- One choice talks mainly about animals hiding quickly.
- Another focuses on the small size of tide pools and whether study is possible.
- Another mentions regret about not sketching the coastline.
- One choice emphasizes the complex way organisms in the tide pool rely on one another.
Only the last of these lines up with the narrator’s comments about “choreography,” “orchestrated” life, and “cataloguing relationships.” Therefore, the correct answer is: The narrator becomes fascinated by the intricate interdependence among the organisms living in a small tide pool.