Mollisols primarily occur in the middle latitudes and are extensive in prairie regions such as the Great Plains of the US. Globally, they occupy ~7.0% of the ice-free land area. In the US, they are the most extensive soil order, accounting for ~21.5% of the land area. Mollisols are among some of the most important and productive agricultural soils in the world and are extensively used for this purpose. Mollisols are divided into 8 suborders: Albolls, Aquolls, Rendolls, Gelolls, Cryolls, Xerolls, Ustolls, and Udolls. Click here for more information about these suborders.
Simple Answer: James Watson and Francis Crick are credited with the first correct double-helix model of DNA structure published in 1953 in the journal Nature.
This Day In History: 02/28/1953 - DNA Structure Discovered. On February 28th many historical events occurred. These events are recapped by Russell Mitchell in this video clip from This Day in History. The discovery of DNA by James Watson and Frances Crick being a major one for the scientific community.