You analyze a dna sample which gives an a260 of 1.74 and a280 of 0.64. what is the concentration of this dna sample? is it sufficiently pure?

The ratio of  indicates the purity of nucleic acid.For pure DNA it should lie between 1.8-2.0.Whereas for RNA it should be greater than 2.

This is calculated for DNA using the given values of absorbance-

= 2.71

As the value is greater than 2.0,it reflects the RNA contamination in the sample.

mountains can affect the climate of nearby lands. in some areas, mountains block rain, so that one side of a mountain range may be rainy and the other side may be a desert. much of airborne moisture falls as rain on the windward side of mountains.

explanation:

the answer is a) cell division.

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