Question 18·200 Super-Hard SAT Reading Questions·Expression of Ideas
While researching a topic, a student has taken the following notes:
- Ecologist Ren Ito offered captive zebra finches large and small seeds from the same grass species.
- The seed batches had comparable shell hardness and concentrations of bitter defensive compounds.
- The finches selected large seeds in 68 percent of their choices.
- In a field survey, ecologist Dana Cruz compared bird removal rates for seeds from 20 wild plant species and found no overall relationship between seed size and removal rate.
- The wild species differed in seed size, shell hardness, and defensive-compound concentration.
- A follow-up experiment found that finches preferred larger seeds when hardness was equal but preferred smaller, softer seeds to larger, harder ones.
The student wants to reconcile Ito’s and Cruz’s findings by explaining how the studies’ designs permit both results to be valid. Which choice most effectively uses relevant information from the notes to accomplish this goal?
For a rhetorical synthesis question asking you to reconcile studies, first identify the apparent disagreement and then compare the studies’ designs. Look for a variable that was controlled in one study but allowed to vary in the other, and use any follow-up evidence to confirm how that difference can produce both results. Avoid choices that declare one study wrong or introduce explanations absent from the notes.
Hints
Compare what varied
Determine which seed characteristics were kept comparable in Ito’s study and which differed in Cruz’s survey.
Examine the follow-up
Consider what the follow-up experiment suggests when seed size and shell hardness favor different choices.
Avoid unsupported explanations
Reject choices that introduce factors such as familiarity or make absolute claims about which single trait controls feeding.
Step-by-step Explanation
Identify the apparent conflict
Ito found that finches preferred larger seeds, but Cruz found no overall relationship between seed size and field removal rates.
Compare the study designs
Ito kept shell hardness and defensive-compound levels comparable. Cruz compared plant species whose seeds differed in size, hardness, and defensive compounds, so size was not the only trait that could affect removal.
Use the follow-up result
The follow-up shows that finches prefer larger seeds when hardness is equal but may choose a smaller seed when it is softer. Thus, a controlled size preference can exist even if size alone does not predict choices across many wild species.