The most important ion in controlling the movement of water into and out of the guard cells is
A. carbon.
B. hydrogen.
C. potassium.
D. nitrogen.
E. sodium.
Answer: C
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What sequence of events usually occurs in the process of protein synthesis?
A) Protein ? RNA ? DNA B) RNA ? DNA ? protein C) DNA ? RNA ? protein D) RNA ? protein ? DNA
The highest elevation at which trees can grow is
A. the Arctic tree line. B. usually determined by salt spray. C. determined by temperature. D. the Antarctic tree line. E. usually determined by oxygen concentration in the atmosphere.
When a scientist sees patterns among a number of isolated facts,
A. laws or principles can be developed. B. the patterns are assumed to have meaning. C. elaborate tests must be developed to see if a cause-and-effect relationship exists. D. as a rule, the pattern must be published.
Which of the following scientists proposed that geologic change occurred gradually due to small changes accumulating over long periods of time?
A. Georges-Louis Leclerc B. Erasmus Darwin C. Jean-Baptist's Lamarack D. James Hutton