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diseases of plants

(Encyclopedia)diseases of plants. Most plant diseases are caused by fungi, bacteria, and viruses. Although the term disease is usually used only for the destruction of live plants, the action of dry rot and the rot...

Cultural Revolution

(Encyclopedia)Cultural Revolution, 1966–76, mass mobilization of urban Chinese youth inaugurated by Mao Zedong in an attempt to prevent the development of a bureaucratized Soviet style of Communism. Mao closed sc...

Tyler, Wat

(Encyclopedia)Tyler, Wat, d. 1381, English rebel. His given name appears in full as Walter; his surname signifies the trade of a roof tiler. He came into prominence as the leader of the rebellion of 1381, known as ...

Stolypin, Piotr Arkadevich

(Encyclopedia)Stolypin, Piotr Arkadevich pyôˈtər ərkäˈdyĭvĭch stəlĭˈpĭn [key], 1862–1911, Russian premier and minister of the interior (1906–11) for Czar Nicholas II. He sought to fight the revoluti...

vasectomy

(Encyclopedia)vasectomy, male sterilization by surgical excision of the vas deferens, the thin duct that carries sperm cells from the testicles to the prostate and the penis. Vasectomy is a popular method of birth ...

Highlands

(Encyclopedia)Highlands, mountain region in the northern extremity of Scotland. It consists roughly of the Scottish area north of the imaginary line from Dumbarton to Stonehaven excluding the Orkneys, the Shetlands...

Ptolemy

(Encyclopedia)Ptolemy (Claudius Ptolemaeus), fl. 2d cent. a.d., celebrated Greco-Egyptian mathematician, astronomer, and geographer. He made his observations in Alexandria and was the last great astronomer of ancie...

plant

(Encyclopedia)plant, any organism of the plant kingdom, as opposed to one of the animal kingdom or of the kingdoms Fungi, Protista, or Monera in the five-kingdom system of classification. (A more recent system, sug...

pear

(Encyclopedia)pear, name for a fruit tree of the genus Pyrus of the family Rosaceae (rose family) and for its fruit, a pome. The common pear (P. communis) is one of the earliest cultivated of fruit trees, both in i...

blood

(Encyclopedia)blood, fluid pumped by the heart that circulates throughout the body via the arteries, veins, and capillaries (see circulatory system; heart). An adult male of average size normally has about 6 quarts...