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mononucleosis, infectious

(Encyclopedia)mononucleosis, infectious mŏnˌəno͞oˌklēōˈsĭs [key], acute infectious disease of older children and young adults, occurring sporadically or in epidemic form, also known as mono, glandular feve...

mesoderm

(Encyclopedia)mesoderm, in biology, middle layer of tissue formed in the gastrula stage of the developing embryo. At the end of the blastula stage, cells of the embryo are arranged in the form of a hollow ball. Con...

myosin

(Encyclopedia)myosin mīˈəsĭn [key], one of the two major protein constituents responsible for contraction of muscle. In muscle cells myosin is arranged in long filaments called thick filaments that lie parallel...

episome

(Encyclopedia)episome ĕpˈĭsōm [key], unit of genetic material composed of a series of genes that sometimes has an independent existence in a host cell and at other times is integrated into a chromosome of the c...

Claude, Albert

(Encyclopedia)Claude, Albert älbârrˈ klōd [key], 1899–1983, Belgian biologist, b. Longlier, M.D., Univ. of Liège, 1928. He joined the Rockefeller Institute (now Rockefeller Univ.) in 1929 and spent his entir...

radioactive isotope

(Encyclopedia)radioactive isotope or radioisotope, natural or artificially created isotope of a chemical element having an unstable nucleus that decays, emitting alpha, beta, or gamma rays until stability is reache...

bone marrow

(Encyclopedia)bone marrow, soft tissue filling the spongy interiors of animal bones. Red marrow is the principal organ that forms blood cells in mammals, including humans (see blood). In children, the bones contain...

kudzu

(Encyclopedia)kudzu ko͝odˈzo͞o [key], plant of the family Leguminosae (pulse family), native to Japan. Kudzu (Pueraria thunbergiana) has a woody stem, broad leaves, and clusters of large purple flowers. It is us...

kohlrabi

(Encyclopedia)kohlrabi kōlˈräˈbē [key] [Ger. partly from Ital.,=turnip cabbage], plant (Brassica caulorapa, sometimes classified as var. caulorapa of the cabbage species) of the family Cruciferae (or Brassicac...

hawkweed

(Encyclopedia)hawkweed, any species of the genus Hieracium of the family Asteraceae (aster family), widely distributed perennials, chiefly of open fields. The small, dandelionlike flower heads are borne in clusters...