The four basic screening bioassays as stated by the authors of the review article are aqueous extract screening, seedling screening, field screening, and chemical screening. Aqueous extract screening involves attempting to germinate seeds or grow plants of a receiver species in soil/solution that contains an extraction from the source species. Seedling screening is the same as aqueous extract screening except ground up donor plant parts or decomposing leaves are mixed into the growth medium. ...

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The calcium sulphate is removed by filtration and the citric acid solution is further purified. Crystallization of citric acid from a hot aqueous solution yields anhydrous citric acid; crystallization from a cold solution yields the monohydrate. ... The neutralized solution must then be evaporated to dryness in a strictly controlled manner to avoid undue losses. ... In the cyanide processes, the most widely used method for extracting gold and silver from the ores, the finely divided ore is contacted with a dilute solution of sodium or potassium cyanide. ... The insoluble polymer protects the...

• Word Count: 1581
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From around 400 million years ago aqueous plants were able to migrate onto the now-protected land and evolve into terrestrial plants, followed by animal life that ate the plants. ... At first sight, the solution to this particular global environmental change appears to be unusually simple: a substitution of particular industrial and agricultural gases for others. ...

• Word Count: 1264
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• Grade Level: Undergraduate