Genealogy

Genealogy is the study of ancestry, or family lineage. Genealogists trace lines of family ancestry and usually show their findings by means of pedigree charts, or genealogical tress. Their study may be relevant to history, law, sociology, or eugenics or their appeal may be more personal, providing people with a sense of continuity and of belonging.

Primitive societies, which are usually organized in tribes or clans, have often sought to trace clan ancestry to gods, legendary heroes, or animals. Clans can thus bolster their identity and strive for divine protection. Lineages were originally transmitted by oral tradition, but later literate societies began to write them down. Notable early Western examples include the genealogies of the tribes of Israel (recorded in the Bible), the Greeks, and the Romans. Genealogies assumed particular importance in connection with the principle of inheritance of power, rank and properly. List of hereditary kings were compiled by the ancient Sumerians, Babylonians, Egyptians, Indian, and Chinese. In medieval Europe feudal landholders kept records for the transference of rank and land. Concern with descent, and thus rank, was also reflected in heraldic developments.

In modern times, social status has depended less on pedigree, but genealogy remains of interest to many people other than scholars. The United States, for example, has numerous genealogical societies that trace people’s descent. The Mormon Church has collected an enormous bank of genealogical data (official registers of births, marriages, and deaths and related documents), probably the greatest such collection in existence, Church members use this records to bring their ancestors posthumously into the church. Popular interest in genealogy was stimulated by the television dramatization of Alex Haley’s Roots (1976); in researching this book Haley had traced his ancestry back to his African forebears.

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Plasmid

Plasmids are small, circular molecules of double stranded deoxyribonucleic acid (DNA) that exist in the cytoplasm of many bacteria. Plasmids carry genes for several different properties, including resistance to various drugs and chemicals, as well as the ability to synthesize toxins that adversely affect foreign species of bacteria. In some cases, plasmids can be rapidly transfer to cell to cell by means of hair-like structure, called sex pilli, that project from the cell surface. Cell to cell plasmid transfer can result in various properties carried on a transmissible plasmid being rapidly disseminated throughout an entire population of bacteria. This property has been responsible fro the appearance of various bacterial populations that are resistant to common antibiotics.

Recently, research involving plasmids has been directed toward gene splicing techniques in the field of genetic engineering. Plasmid DNA is isolated from bacteria, and its circular structure is broken by specific enzymes. A foreign DNA segment is then inserted in the plasmid, and the circle is resealed by other enzymes. A foreign DNA segment is then inserted in the plasmid, and the circle is resealed by other enzymes. This reconstructed plasmid, which contains an extra gene, can be replaced in the bacterial cell. Under the proper conditions the cell will synthesize the product of the foreign gene as well as those codec by its own DNA.

Those technique use on DNA engineering on how modification a gene from specific source, may come from bacteria or viruses or from plant, then create a new cell that can be use to destroy cancer cell for example. The technique to cut this DNA is use certain enzyme. This enzyme also can directly use for cancer drug that can directly to destroy a cancer cell through DNA information code that always reproduce by themselves. The reproduction of cancer cell can be stop by cut the right information DNA.