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aphid

(Encyclopedia)aphid or plant louse, tiny, usually green, soft-bodied, pear-shaped insect injurious to vegetation. It is also called greenfly and blight. Aphids are mostly under 1⁄4 in. (6 mm) long. Some are wingl...

in vitro fertilization

(Encyclopedia)in vitro fertilization vēˈtrō, vĭˈtrō [key] (IVF), technique for conception of a human embryo outside the mother's body. Several ova, or eggs, are removed from the mother's body and placed in sp...

medicine

(Encyclopedia)medicine, the science and art of treating and preventing disease. Modern medicine, characterized by growing specialization and a complex diagnostic and therapeutic technology, faces problems in the...

schizophrenia

(Encyclopedia)schizophrenia skĭtˌsəfrēˈnēə [key], group of severe mental disorders characterized by reality distortions resulting in unusual thought patterns and behaviors. Because there is often little or n...

vineyard

(Encyclopedia)vineyard, land on which cultivation of the grape—known as viticulture—takes place. As many as 40 varieties of grape, Vitis vinifera, are known. The few that grow wild are generally not used; all d...

cigar and cigarette

(Encyclopedia)cigar and cigarette, tubular rolls of tobacco designed for smoking. Cigars consist of filler leaves held together by binder leaves and covered with a wrapper leaf, which is rolled spirally around the ...

genetic engineering

(Encyclopedia)CE5 Genetic engineering: Gene-splicing techniques genetic engineering, the use of various methods to manipulate the DNA (genetic material) of cells to change hereditary traits or produce biologica...

plague

(Encyclopedia)plague, any contagious, malignant, epidemic disease, in particular the bubonic plague and the black plague (or Black Death), both forms of the same infection. These acute febrile diseases are caused b...

mental retardation

(Encyclopedia)mental retardation, below average level of intellectual functioning, usually defined by an IQ of below 70 to 75, combined with limitations in the skills necessary for daily living. Daily living skills...

mouse

(Encyclopedia)mouse, name applied to numerous species of small rodents, often having soft gray or brown fur, long hairless tails, and large ears. The chief distinction between these animals and the variety of roden...