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birth defects

(Encyclopedia)birth defects, abnormalities in physical or mental structure or function that are present at birth. They range from minor to seriously deforming or life-threatening. A major defect of some type occurs...

louse

(Encyclopedia)louse, common name for members of either of two distinct orders of wingless, parasitic, disease-carrying insects. Lice of both groups are small and flattened with short legs adapted for clinging to th...

cockroach

(Encyclopedia)cockroach or roach, name applied to some 4,600 species of flat-bodied, oval insects in the order Blattodea. Cockroaches have long antennae, long legs adapted to running, and a flat extension of the up...

polymerase chain reaction

(Encyclopedia)polymerase chain reaction pŏlˈĭmərāsˌ [key] (PCR), laboratory process in which a particular DNA segment from a mixture of DNA chains is rapidly replicated, producing a large, readily analyzed sa...

rue

(Encyclopedia)rue, common name for various members of the family Rutaceae, a large group of plants distributed throughout temperate and tropical regions and most abundant in S Africa and Australia. Most species are...

Aachen

(Encyclopedia)Aachen bät äˈkhən [key], city, North Rhine–Westphalia, W Germany, near the Belgian and Dutch borders. One of the great historic cities of Europe, it is now chiefly i...

bacteria

(Encyclopedia)bacteria [pl. of bacterium], microscopic unicellular prokaryotic organisms characterized by the lack of a membrane-bound nucleus and membrane-bound organelles. Once considered a part of the plant king...

virus

(Encyclopedia)CE5 Structure of a tobacco mosaic virus, an RNA-containing virus virus, parasite with a noncellular structure composed mainly of nucleic acid within a protein coat. Most viruses are too small (100...

circumcision

(Encyclopedia)circumcision sûrˌkəmsĭzhˈən [key], operation to remove the foreskin covering the glans of the penis. It dates back to prehistoric times and was widespread throughout the Middle East as a religio...

peanut

(Encyclopedia)peanut, name for a low, annual leguminous plant (Arachis hypogaea) of the family Leguminosae (pulse family) and for its edible seeds. Native to South America and cultivated there for millenia, it is s...