siddreal wrote:
Which of the following most logically completes the argument?
A certain cultivated herb is one of a group of closely related plants that thrive in soil with high concentrations of metals that are toxic to most other plants. Agronomists studying the herb have discovered that it produces large amounts of histidine, an amino acid that, in test-tube solutions, renders these metals chemically inert. Possibly, therefore, the herb's high histidine production is what allows it to grow in metal-rich soils, a hypothesis that would gain support if ______.
A. histidine is found in all parts of the plant-roots, stem, leaves, and flowers
B. the herb's high level of histidine production is found to be associated with an unusually low level of production of other amino acids
C. others of the closely related group of plants are also found to produce histidine in large quantities
D. cultivation of the herb in soil with high concentrations of the metals will, over an extended period, make the soil suitable for plants to which the metals are toxic
E. the concentration of histidine in the growing herb declines as the plant approaches maturity
This is a CAUSAL argument.
In a causal argument, A and B are observed together, and the CR concludes that A CAUSES B.
Premise = A and B are observed together:A cultivated herb produces histidine and is able to grow in metal rich soils.
Conclusion = A causes B:Histidine CAUSES the herb to be able to grow in metal rich soils.
One way to strengthen the conclusion that A causes B is give ANOTHER SUPPORTING EXAMPLE that links A to B.
C:
others of the closely related group of plants are also found to produce histidine in large quantities.
Here, other plants in the closely related group THAT THRIVE IN SOIL WITH HIGH CONCENTRATIONS OF METALS also produce HISTIDINE, STRENGTHENING the conclusion that histidine CAUSES a plant to be able to grow in metal-rich soils.
The posted OA is incorrect.
The OA to the CR above is virtually the same as the OA to CR644 in the OG18:
Quote:
A certain cultivated herb is one of a group of closely related plants that thrive in soil with high concentrations of metals that are toxic to most other plants. Agronomists studying the growth of this herb have discovered that it produces large amounts of histidine, an amino acid that, in test‐tube solutions, renders these metals chemically inert. Hence, the herb’s high histidine production must be the key feature that allows it to grow in metal‐rich soils.
In evaluating the argument, it would be most important to determine which of the following?
A) Whether the herb can thrive in soil that does not have high concentrations of the toxic metals
B) Whether others of the closely related group of plants also produce histidine in large quantities
C) Whether the herb’s high level of histidine production is associated with an unusually low level of production of some other amino acid
D) Whether growing the herb in soil with high concentrations of the metals will, over time, reduce their concentrations in the soil
E) Whether the concentration of histidine in the growing herb declines as the plant approaches maturity”
The OA to CR644 is:
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Updated on: 15 Jun 2018, 08:11
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