What is DNA from a Genealogical Perspective, Part II

DNA science is replete with a lot of terms, some of them almost unpronounceable, so understanding their meaning and relationship is not a given. In his article, "What is DNA from a Genealogical Perspective, Part II," Alan Smith provides some clarification. And while the genetic function of the DNA "parts" is important and interesting, the article makes the point that genealogists are primarily concerned with the hereditary aspect of DNA and what we can hope to learn from DNA testing that will advance our research.