Vocabulary in Context: 'Arrest' in Cell Biology
An OAT passage on cell biology states: 'During prophase, the cell arrests its normal activities and condenses its chromosomes. This arrest is not passive; checkpoint proteins actively hold the cycle until damage is repaired. If repair fails, the cell may trigger programmed death.' A vocabulary question asks for the meaning of 'arrests' as used in the first sentence. Options are (A) detains legally, (B) stops, (C) seizes suddenly, (D) captures attention. A second question asks which assumption underlies the claim that the arrest is 'not passive.' The student, a former debate competitor, knows 'arrest' from legal contexts and initially favors A; she also wonders whether the second question can be answered from the sentence alone. She has 90 seconds left.
1. Select the correct meaning of 'arrests' and show why the legal sense fails here.
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B, stops. The sentence's second half supplies the clue: the cell 'condenses its chromosomes,' a process that begins when routine activity halts. The next sentence reinforces this by calling the halt an 'arrest' that checkpoint proteins 'hold' - a pause in a cycle. Substitute each option: 'detains its normal activities' imports a legal actor and sounds odd, while 'stops its normal activities' is idiomatic and process-appropriate. The legal sense is a real meaning of the word but belongs to the wrong domain. Vocabulary-in-context questions ask what the word does in this sentence, not what it most often means elsewhere.
2. Why is 'captures attention' tempting but wrong?
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It is a common meaning of 'arrest' - a sight can arrest a viewer - but it requires a perceiver whose attention is captured. Here the subject is a cell and the object is 'its normal activities'; activities are not spectators. The test is selectional: ask what kinds of things can serve as the object of the verb. Activities can be stopped; they cannot be captivated. Option D fails on that restriction alone, before any biology is considered. Noticing the object is often enough to eliminate a plausible-sounding but domain-mismatched definition.
3. What assumption underlies the claim that the arrest is 'not passive,' and can it be supplied from the sentence itself?
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The claim assumes that stopping the cycle is not the default - that, left alone, the cycle would proceed - and that holding it therefore requires active machinery. The sentence supplies the machinery ('checkpoint proteins actively hold'), so the missing premise concerns the default: without those proteins, the cell would continue. A smaller assumption is that 'active' means protein- or energy-mediated rather than merely observable. The student does not need outside biology: the contrast word 'not passive' plus 'actively hold' sets up the premise. If the cycle would stall on its own, the claim would be false.