The sequence of bases on DNA codes for the sequence of amino acids in proteins. But there are 20 different amino acids and only 4 different bases, so the bases are read in groups of 3. This gives 64 combinations, more than enough to code for 20 amino acids.
10 cheapest places to live in the U.S. Ashland, Ohio, ranks as the 10th most affordable city in the U.S., according to the Council for Community and Economic Research. Ashland has a cost of living index of 87.6.
Following is a look at each of the 10 most expensive cities in the United States. 1. Manhattan, New York Manhattan, New York, once again ranks as the most expensive place to live in the U.S. The city in 2012 had cost of living index of 225.4 -- more than double the national average.