Question 156·Hard·Central Ideas and Details
Researchers studying seed dormancy reported that several Nelumbo nucifera (sacred lotus) seeds recovered from the dried bed of an ancient lake germinated after roughly 1,300 years. When the scientists compared these ancient seeds with freshly harvested ones, they observed no meaningful difference in germination success or early seedling growth. The researchers concluded that lotus seeds possess an internal biological mechanism that halts cellular aging. According to the study, most plant seeds lose viability after a few decades because their tissues slowly deteriorate, but lotus seeds remain viable as long as two conditions are met: their exceptionally tough outer coat stays intact, and the seeds are kept dry. This discovery is motivating further research into whether compounds in the lotus seed coat might help extend the shelf life of important crop seeds.
What does the text most strongly suggest enables lotus seeds to remain viable for more than a millennium?
For central-idea/detail questions, locate the most explicit explanatory sentences (especially those with signals like “concluded,” “according to the study,” and “as long as”). Treat any listed conditions as a checklist: the best answer should include all required conditions and avoid adding causes the passage doesn’t support.
Hints
Focus on the sentences that explain the cause
Look for the part of the passage that explains why most seeds lose viability and then contrasts that with why lotus seeds don’t.
Find the statement with a condition
Locate the sentence that says lotus seeds remain viable “as long as two conditions are met,” and note both conditions.
Don’t ignore the researchers’ conclusion
The passage also includes a conclusion about what happens to cellular aging in lotus seeds. Make sure the best answer reflects that conclusion and the listed conditions.
Step-by-step Explanation
Identify what the question is asking
The question asks what the text most strongly suggests enables lotus seeds to remain viable for more than a millennium, so you should look for the passage’s stated explanation for their long-lasting viability.
Pull the key claims from the passage
The passage gives two key pieces of information about why the seeds can last so long:
- The researchers concluded lotus seeds have an internal biological mechanism that halts cellular aging.
- The study says lotus seeds remain viable as long as two conditions are met: (1) their outer coat stays intact and (2) the seeds are kept dry.
Eliminate choices that omit or distort those claims
Eliminate any choice that:
- says viability is independent of conditions (the passage says it depends on two conditions), or
- mentions only one condition (dryness alone or coat alone), or
- assigns the anti-aging effect to the coat rather than to the internal mechanism.
Choose the option that matches the passage exactly
The only choice that combines the passage’s internal-mechanism conclusion with the two required conditions (coat intact and kept dry) is:
An internal mechanism halts cellular aging, allowing the seeds to stay viable when their outer coat remains intact and they are kept dry.