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Tay-Sachs disease

(Encyclopedia)Tay-Sachs disease tāˈ-săksˈ [key], rare hereditary disease caused by a genetic mutation that leaves the body unable to produce an enzyme necessary for fat metabolism in nerve cells, producing cent...

artificial insemination

(Encyclopedia)artificial insemination, technique involving the artificial injection of sperm-containing semen from a male into a female to cause pregnancy. Artificial insemination is often used in animals to multip...

whist

(Encyclopedia)whist, card game for four players, those on opposite sides of the table being partners. The full pack of 52 cards is dealt. The dealer's last card is turned up to indicate trump, and after he draws th...

Trajan

(Encyclopedia)Trajan (Marcus Ulpius Trajanus) trāˈjən [key], c.a.d. 53–a.d. 117, Roman emperor (a.d. 98–a.d. 117). Born in Spain, he was the first non-Italian to become head of the empire. Trajan served in t...

genetics

(Encyclopedia)genetics, scientific study of the mechanism of heredity. While Gregor Mendel first presented his findings on the statistical laws governing the transmission of certain traits from generation to genera...

kindergarten

(Encyclopedia)kindergarten [Ger.,=garden of children], system of preschool education. Friedrich Froebel designed (1837) the kindergarten to provide an educational situation less formal than that of the elementary s...

kidnapping

(Encyclopedia)kidnapping, in law, the taking away of a person by force, threat, or deceit, with intent to cause him to be detained against his will. Kidnapping may be done for ransom or for political or other purpo...

adoption

(Encyclopedia)adoption, act by which the legal relation of parent and child is created. Adoption was recognized by Roman law but not by common law. Statutes first introduced adoption into U.S. law in the mid-19th c...

ovum

(Encyclopedia)ovum ōˈvəm [key], in biology, specialized plant or animal sex cell, also called the egg, or egg cell. It is the female sex cell, or female gamete; the male gamete is the sperm. The study of the ovu...

colonization

(Encyclopedia)colonization, extension of political and economic control over an area by a state whose nationals have occupied the area and usually possess organizational or technological superiority over the native...