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myoglobin

(Encyclopedia)myoglobin mīˌəglōˈbĭn [key], protein molecule isolated from the cells of vertebrate skeletal muscle that is both a structural and functional relative of hemoglobin, the oxygen-transport protein ...

osmium

(Encyclopedia)osmium ŏzˈmēəm [key], metallic chemical element; symbol Os; at. no. 76; at. wt. 190.23; m.p. 3,045±30℃; b.p. 5,027±100℃; sp. gr. 22.57 at 20℃; valence usually +0 to +8. Osmium is a very ha...

mass extinction

(Encyclopedia)mass extinction, the extinction of a large percentage of the earth's species, opening ecological niches for other species to fill. There have been at least ten such events. The five greatest were thos...

chromium

(Encyclopedia)chromium krōˈmēəm [key] [Gr.,=color], metallic chemical element; symbol Cr; at. no. 24; at. wt. 51.9961; m.p. about 1,857℃; b.p. 2,672℃; sp. gr. about 7.2 at 20℃; valence +2, +3, +6. Chromiu...

bromine

(Encyclopedia)bromine brōˈmēn, –mĭn [key] [Gr.,=stench], volatile, liquid chemical element; symbol Br; at. no. 35; at. wt. 79.904; m.p. –7.2℃; b.p. 58.78℃; sp. gr. of liquid 3.12 at 20℃; density of va...

liana

(Encyclopedia)liana lēänˈ [key], name for any climbing plant that roots in the ground. The term is most often used for the woody vines that form a characteristic part of tropical rain-forest vegetation; they are...

flying lemur

(Encyclopedia)flying lemur, gliding mammal native to the tropical lowland forests of S Asia, Malaya, and the Philippines. Also called the colugo, the flying lemur is brownish or grayish above and paler below. It ra...

Salt River valley

(Encyclopedia)Salt River valley, irrigated region around the lower course of the Salt River, which rises in mountain streams near the Mogollon Rim of the Mogollon Plateau and flows southwest to join the Gila River ...

addax

(Encyclopedia)addax ădˈăks [key], large, desert-dwelling antelope. It is a single species, Addax nasomaculatus. The addax is yellowish-white in color, has a brown mane and throat fringe, and may stand as high as...

umbrella

(Encyclopedia)umbrella, a small canopy used as a protection against the sun in China, Egypt, and elsewhere in remote antiquity. It was often an emblem of rank. During the Middle Ages the umbrella became almost exti...