A main idea question about a study tests whether you can state what the results show overall. Start by naming the topic and the view being tested, then follow what the researchers found rather than what they did. With more than one test, ask what each adds to the point. Predict one sentence that covers all the findings, then check how much each choice claims. A choice can repeat a real result and still miss or overstate the overall point.
Hints
- Hint 1
The text starts with a proposed reason for field mosses' faster recovery. Follow what each test says about that proposal.
- Hint 2
In the genetically identical shoots, compare recovery after repeated drying with recovery after eight weeks of moisture. What does the change over time tell you about the earlier advantage?
- Hint 3
In the last sentence, separate what the team saw from why it might have happened. What point can you make that includes both tests and stays within what they show?
Step-by-step
Follow the results across both tests
Step 1Name the topic and the tested view
The text names inherited adaptation as a proposed reason why field mosses recover faster than laboratory mosses. Is that the writer's point, or a view the team tests? It's the tested view, so the main idea must come from what the team found.
- Step 2
Trace the first result over time
The team divides genetically identical shoots between drying and constant moisture, so what can explain the faster recovery in the dried group? Inherited differences can't explain it because the shoots share the same genes. Later, the advantage largely disappeared after eight weeks of continuous moisture, and new growth recovered slowly too. The drying advantage faded after the conditions changed.
- Step 3
Add the site finding without proving its cause
The separate test finds that shoots retained distinct recovery rates even after receiving the same drying treatment. Does matching that treatment prove that genes caused the remaining gap? We know the drying treatment matched, but the text doesn't show that the shoots differed only in their genes. The site differences lasted through that treatment, but we still don't know what caused them. Our prediction is that drying can have an effect that fades, while some site differences last through shared drying.
- Step 4
Check the answer's coverage and certainty
Which wording covers both tests without claiming more than they show? Reversible effects fits an advantage that can fade, while more persistent differences means lasting through the shared treatment, not necessarily forever. The phrase appears to reflect doesn't claim to know what caused those site differences, so it doesn't treat lasting differences as proof of inheritance. Choice D.