Examkin

Soru

Zorluk: OrtaWeaken

Marine Biologist: Over the past decade, populations of native ribbon kelp in the North Sound estuary declined by sixty percent. During the same period, water salinity in the estuary dropped significantly due to increased agricultural runoff from nearby farms. Because laboratory experiments confirm that juvenile ribbon kelp tissue suffers cellular degradation when exposed to reduced salinity, the decline in North Sound's ribbon kelp must be primarily caused by this agricultural runoff.

Which of the following statements, if true, undermine the marine biologist's argument? (Select all that apply.)

  1. An invasive species of herbivorous sea urchin that feeds voraciously on mature ribbon kelp was introduced to the North Sound estuary ten years ago and has since multiplied substantially.Cevap
  2. B
    Nearby coastal inlets with comparable increases in agricultural runoff and salinity drops recorded identical decreases in ribbon kelp density over the same decade.
  3. The agricultural runoff entering the estuary contains dissolved nutrients that neutralize cellular stress in juvenile ribbon kelp, keeping juvenile survival rates in North Sound consistent with historical averages.Cevap
  4. D
    Adult ribbon kelp tissues tested in laboratory environments do not show cellular degradation under reduced salinity conditions.
  5. E
    Agricultural runoff is known to be the most damaging ecological pollutant across all marine flora worldwide.

Cevap

The argument is undermined by the statements identifying an alternative cause (the proliferation of an invasive kelp predator) and showing that local runoff conditions prevent the juvenile mortality observed in laboratory settings.
The argument concludes that agricultural runoff caused the kelp decline based on a concurrent drop in salinity and laboratory tests on juvenile kelp. The statement regarding the invasive sea urchin undermines the conclusion by introducing a plausible alternative cause that occurred over the same timeframe. The statement regarding dissolved nutrients neutralizing cellular stress in the wild weakens the argument by showing that the laboratory findings do not apply to the actual conditions in the estuary.

Adım Adım Çözüm

1
Identify the conclusion and supporting premises in the stimulus.
Conclusion: The decline in North Sound's ribbon kelp was primarily caused by agricultural runoff. Premises: Salinity dropped due to runoff over the past decade, and laboratory tests show juvenile kelp tissue degrades in low salinity.
Isolating the core causal claim is essential for evaluating potential counterevidence.
2
Identify the logical assumptions connecting the premises to the conclusion.
The author assumes no other major confounding factor caused the decline, and that laboratory observations directly translate to wild estuary conditions.
Weakeners target unstated assumptions or provide alternative explanations for observed phenomena.
3
Evaluate each option against the causal chain.
The option introducing an invasive grazing sea urchin provides an alternate cause, while the option showing nutrient buffering in the estuary breaks the link between laboratory data and wild outcomes.
Both findings directly reduce the likelihood that agricultural runoff was the primary driver of the population decline.

Anahtar Kavram

Weakening causal arguments by introducing alternative explanations or invalidating the application of experimental data to wild conditions
Bu soruyu puanla

Konular

Weaken

Bu konudan daha fazla soru