Command of Textual Evidence on the SAT Reading and Writing section asks a student to choose the quotation or finding that most directly supports, illustrates, or weakens a claim. After a scholarly or scientific scenario, the student must pick the option that best backs a historian's argument, most clearly undercuts a lab hypothesis, or shows that paired examples really do what the writer claims. Questions typically ask which quotation from an article is strongest, or which finding, if true, would most support or weaken that claim. Traps are related but off-target evidence and quotations that restate an idea without proving it. Answer choices are brief quotations or compact hypothetical results.
Question 1
Historian Amira Cole argues that the labels on early botanical specimens did more than identify plants: because collectors repeatedly revised the labels as classifications changed, the labels also preserve evidence of scientific disagreement over time.
Which quotation from Cole’s article most effectively illustrates the claim?
- A“Many specimen sheets contain plants gathered during expeditions that lasted several months.”
- B“Collectors generally wrote labels in ink so that the plant names would remain legible.”
- C“On some sheets, one species name is crossed out and replaced by another, while a later note disputes both identifications.”
- D“Botanical archives often store specimens in cabinets organized by geographic region.”
Show answer
Answer: C — “On some sheets, one species name is crossed out and replaced by another, while a later note disputes both identifications.”
The crossed-out, replaced, and disputed identifications directly show labels recording changing scientific judgments.
Question 2
Conservation biologists hypothesize that a waxy coating made by bacterium B7 protects marsh-grass seeds from salt damage. In laboratory trials, seeds carrying B7 survived salt exposure more often than seeds without the bacterium.
Which finding, if true, would most directly weaken the biologists’ hypothesis?
- AB7-carrying seeds produced more of the waxy coating in fresh water than in salt water.
- BRemoving the genes that produce B7’s waxy coating did not reduce the survival of B7-carrying seeds under salt exposure.
- CSeeds without B7 survived salt exposure more often after a protein film from a different marsh bacterium was applied to them.
- DThe waxy coating also reduced water loss from seeds stored in dry air.
Show answer
Answer: B — Removing the genes that produce B7’s waxy coating did not reduce the survival of B7-carrying seeds under salt exposure.
If disabling production of the waxy coating does not reduce salt survival, the coating is unlikely to be the cause of the protection.
Question 3
A university radio station ran two limited series last year: Fault Lines, about predicting structural failure, and Synapse Hour, about how brains parse speech. Taken together, the series illustrate the breadth of scientific fields the station is willing to put on air.
Which finding, if true, would most directly support the underlined claim?
- AFault Lines episodes cited geology, metallurgy, and civil engineering, while Synapse Hour episodes drew on psychology, neurology, and linguistics.
- BBoth series drew their experts from subfields of a single discipline, engineering.
- CBoth series were recorded in the same on-campus studio and used the same theme music.
- DBoth series devoted most of their episodes to competing explanations of a single research problem within their respective fields.
Show answer
Answer: A — Fault Lines episodes cited geology, metallurgy, and civil engineering, while Synapse Hour episodes drew on psychology, neurology, and linguistics.
Naming several distinct disciplines across the two series directly supports a claim about scientific breadth; experts from one discipline, shared production details, and concentrating on one research problem within each field do not.
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