The plants and animals that live and then die are the bio part; the earth that they decompose into comprises the geo part; and the process by which organic matter returns to the chemical elements in the earth is explained by the chemical part. There are four biogeochemical cycles, and each of them returns to the earth important elements that are required in living organisms.the four cycles include (a) The water cycle(b)The Carbon Cycle ,(c) The phosphorous cycle, (d) The Nitrogen cycle
Review articles are the summary of current state of understanding on a particular research topic. They analyze or discuss research previously published by scientist and academicians rather than reporting novel research results.
Review article comes in the form of systematic reviews and literature reviews and are a form of secondary literature. Systematic reviews determine an objective list of criteria, and find all previously published original research papers that meet the criteria. They then compare the results presented in these papers. Literature reviews, by contrast, provide a summary of what the authors believe are the best and most relevant prior publications.
The concept of "review article" is separate from the concept of peer-reviewed literature. It is possible for a review to be peer-reviewed, and it is possible for a review to be non-peer-reviewed.
Last date updated on July, 2014