Question 57·Hard·Rhetorical Synthesis
While researching a topic, a student has taken the following notes:
• The Venus flytrap (Dionaea muscipula) is a carnivorous plant native to the coastal wetlands of North and South Carolina.
• Each trap closes only when two different sensory hairs are touched within about 20 seconds, preventing false alarms.
• The closing mechanism is driven by rapid changes in cell pressure, not by muscular tissue.
• The trap snaps shut in roughly 0.1 seconds, making it one of the fastest movements in the plant kingdom.
The student wants to add a sentence to a paragraph that explains how some plants can execute rapid movements through internal pressure changes. Which choice most effectively uses relevant information from the notes to accomplish this goal?
For rhetorical synthesis questions like this, start by underlining the exact goal in the prompt (here, explaining rapid plant movement through internal pressure changes). Then scan the notes and quickly list the few key facts that relate directly to that goal. Next, test each answer choice against two criteria: (1) it must include those key facts (or a clear subset of them) and directly support the stated goal, and (2) it must not contradict the notes or introduce new, unsupported ideas. Eliminate any option that changes the mechanism, adds invented details, or shifts focus away from the goal, and select the remaining sentence that is both accurate and most clearly on-purpose.
Hints
Focus on the task phrase
Look back at the prompt: the sentence must explain how some plants can execute rapid movements through internal pressure changes. Which note talks about that mechanism?
Use only what’s in the notes
For each choice, ask: Is every detail directly supported by the bullet points? Eliminate any option that introduces new ideas (like causes or effects) that do not appear in the notes.
Check for mechanism and speed together
Among the answers that are factually accurate, which one clearly connects how fast the trap moves with changes in internal cell pressure, while still fitting the idea of giving an example?
Step-by-step Explanation
Understand the goal of the new sentence
The question says the paragraph is about how some plants can execute rapid movements through internal pressure changes. So the new sentence must:
- Give an example of a plant with rapid movement.
- Make clear that the movement happens because of internal pressure changes, not muscles or something else.
- Use only information that comes from the notes.
Pull out the key details from the notes
From the notes, the most important points for this task are:
- The Venus flytrap is a carnivorous plant from coastal wetlands of North and South Carolina.
- Its trap closes only when two different sensory hairs are touched within about 20 seconds, which prevents false alarms.
- The closing mechanism is driven by rapid changes in cell pressure, not by muscular tissue.
- The trap snaps shut in roughly 0.1 seconds, making it one of the fastest plant movements.
For this question, the crucial ideas are:
- Rapid movement: snapping shut in about 0.1 seconds.
- Internal pressure changes: movement driven by changes in cell pressure, not muscles.
- The two-hair trigger and native location can be included as long as they stay accurate and relevant.
Eliminate choices that conflict with the notes or the goal
Now compare each option to the notes and the writing goal:
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Choice A says the Venus flytrap "depends on muscle-like fibers" and closes when any single hair is touched. This contradicts the notes, which say the movement is driven by cell pressure, not muscular tissue, and that two different hairs must be touched.
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Choice C correctly states the fast closing time, but then claims that because it lives in North and South Carolina, it rarely mistakes raindrops for prey. The notes never mention raindrops or link false alarms to its location. Also, this choice never explains the pressure-based mechanism, so it doesn’t meet the goal.
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Choice D says the plant closes quickly because "two hairs must be touched" and that the "real reason" is that it is carnivorous. The notes say the two hairs prevent false alarms, not that they cause speed, and that the motion is due to cell pressure, not carnivory. It also fails to mention internal pressure changes.
Only one choice stays fully accurate and actually links the Venus flytrap’s rapid movement to changes in cell pressure, using details from the notes (speed, trigger hairs, and habitat) without inventing new facts.
Confirm the best match to the task
The choice that does all of the following is correct:
- Identifies the Venus flytrap as a carnivorous plant from coastal Carolina wetlands.
- Explains that it demonstrates rapid plant motion.
- States that it alters cell pressure (the key internal mechanism) to close its trap in about 0.1 seconds.
- Accurately adds that this happens only after two hairs are contacted within about 20 seconds, matching the notes.
Therefore, the correct answer is:
“The Venus flytrap, a carnivorous species from coastal Carolina wetlands, exemplifies rapid plant motion: it alters cell pressure to close its trap in as little as 0.1 seconds, but only after two trigger hairs are contacted within about 20 seconds.”