Biology: evidence and generalization

Read one sustained passage and answer eight questions before reviewing the feedback.

Paper packet. Every task here also exists on screen, where it is checked automatically; answers written on paper are not assessed by Nydus. When you are back at a device, enter your answers there.

1. What you will learn

Map the passage, answer all eight questions and explain each rejected rival using the text.

2. Practice

Read the shared passage and answer every question before submitting. These are original instructional questions; a repeated passage is review, not fresh diagnostic evidence.

[1] A hypothetical research team compared the survival of seedlings planted beneath artificial shade with that of seedlings planted in open plots. The shaded seedlings survived more often during the first dry month. Because the experiment used randomly assigned plots with similar soil, the team regarded the result as evidence that shade could improve early survival under the tested conditions. The report did not claim that shade was beneficial at every stage of growth or in every climate.

[2] The team measured soil moisture weekly. Shaded plots retained more moisture between waterings, a finding consistent with reduced evaporation as one possible mechanism. However, the experiment did not separately manipulate evaporation while holding every other consequence of shade constant. Shade also changes light availability and can change temperature. The moisture measurements therefore supported a plausible explanation without establishing that moisture retention was the only pathway responsible for the survival difference.

[3] A second phase followed the surviving plants after the dry period. Growth rates then differed less consistently between the groups. This did not erase the earlier survival result: survival during a particular month and later growth rate are distinct outcomes. It did, however, limit a simple recommendation to shade every seedling indefinitely. A practice useful during an establishment period might need to change as the plants' needs and environmental conditions changed.

[4] The researchers recommended additional trials across seasons and species before adopting a broad planting policy. They also noted that the artificial shade structures were kept in good repair throughout the experiment. A community program unable to maintain such structures might not reproduce the same conditions. These qualifications are not admissions that the experiment taught nothing. Rather, they identify what the evidence supports and what remains to be tested. The central contribution is a bounded result about early survival, accompanied by a plausible but incompletely isolated mechanism. Reading the report as either a universal endorsement of shade or a complete failure would discard the distinctions that make the study informative. The next useful question is which conditions preserve the benefit and which change its costs, not whether one limited finding can settle every planting decision.

Which statement is explicitly supported by the report as described?

Moisture retention was isolated as the only cause of better survival.
Every species benefits from permanent shade.
The shade structures were left unrepaired.
Later growth differences were more consistent than early survival differences.
Shaded plots retained more soil moisture between waterings during the measurements.

Which inference about the authors' recommendation is best supported?

Maintenance cannot affect the applicability of the results.
Later growth proves no seedling benefited earlier.
A broad policy would need evidence beyond the initial survival result.
The authors believe the initial trial was worthless.
The authors have already tested every relevant climate.

Calling the mechanism 'incompletely isolated' indicates that:

the design did not separate moisture effects from all other effects of shade
the plots were not physically separated
the team collected no moisture measurements
the survival difference was absent
the later phase proved moisture irrelevant

The reference to maintaining the shade structures functions chiefly to:

explain why later growth must exceed early survival
show that artificial shade has no practical use
establish maintenance as the only survival mechanism
identify a condition that may limit transfer to a community program
reveal that random assignment was unsuccessful

Which principle best fits the researchers' recommendation?

Prefer interventions that require no maintenance regardless of benefit
Extend a useful intervention only as far as evidence about relevant conditions supports
Withhold every recommendation until all possible mechanisms are known
Treat any randomized result as universal
Use later growth as the sole measure of an earlier survival intervention

Which comparison best matches the distinction between early survival and later growth?

Two thermometers measure the same temperature with different units
An experiment fails to record any result
An observer mistakes one plant species for another
A study repeats an identical test under identical conditions
A tutoring program improves course completion but has uncertain effects on later employment

Which result would most strengthen the proposed moisture mechanism?

Unshaded plants have higher later growth in a different climate
Participants find shaded plots more attractive
Equalizing moisture while retaining the other shade differences largely removes the survival difference
Shaded plots again show higher survival without any further measurements
The artificial structures are cheaper in a later season

A new species shows no survival benefit under the same shade treatment. This finding would:

limit generalization across species without by itself reversing the original result
prove that the original random assignment never occurred
show that shade cannot affect any species
establish moisture as the only cause of the first result
make further trials across species unnecessary

3. What you can do now

Tomorrow, recall the passage's central distinction and your most useful correction. Next week, use a different set before revisiting this one. Familiar passages provide retrieval practice, not an independent baseline.