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behavior

(Encyclopedia)behavior, in biology: see ethology. ...

stem cells

(Encyclopedia)stem cells, unspecialized human or animal cells that can produce mature specialized body cells and at the same time replicate themselves. Embryonic stem cells are derived from a blastocyst (the blastu...

paramecium

(Encyclopedia)paramecium parəmēˈsĭəm [key], unicellular organism of the genus Paramecium, of the ciliate phylum Ciliophora found in freshwater throughout the world. Like other protozoans, paramecia, previously...

melanin

(Encyclopedia)melanin mĕlˈənĭn [key], water-insoluble polymer of various compounds derived from the amino acid tyrosine. It is one of two pigments found in human skin and hair and adds brown to skin color; the ...

Hunt, R. Timothy

(Encyclopedia)Hunt, R. Timothy (Richard Timothy Hunt), 1943–, British biochemist, Ph.D. Cambridge, 1968. Hunt was a researcher at the Albert Einstein College of Medicine, New York City (1968–81) and a professor...

meiosis

(Encyclopedia)CE5 Formation of sperm cells through meiosis meiosis mīŏˈsĭs [key], process of nuclear division in a living cell by which the number of chromosomes is reduced to half the original number. Meio...

Steinman, Ralph Marvin

(Encyclopedia)Steinman, Ralph Marvin, 1943–2011, Canadian biologist, M.D. Harvard Medical School, 1968. He was a researcher and professor at Rockefeller Univ., New York City, from 1970 until his death in 2011. St...

Szostak, Jack William

(Encyclopedia)Szostak, Jack William, 1952–, American molecular biologist, b. London, England, Ph.D. Cornell, 1977. Szostak has been a professor at Harvard Medical School and a researcher at Massachusetts General ...

Köhler, Georges Jean Franz

(Encyclopedia)Köhler, Georges Jean Franz kōˈlər, Ger. köˈlər [key], 1946–95, German immunologist, Ph.D. Univ. of Freiburg, 1974. He worked (1974–76) with César Milstein at the Laboratory of Molecular Bi...

ribosome

(Encyclopedia)ribosome: see cell; nucleic acid. ...