Columbia Encyclopedia

Search results

30 results found

operon

(Encyclopedia)operon, in genetics, site on a bacterial chromosome containing genes that control protein synthesis (structural genes) together with a gene that determines whether the structural genes are active or n...

Wilson, Edmund Beecher

(Encyclopedia)Wilson, Edmund Beecher, 1856–1939, American zoologist, b. Geneva, Ill., grad. Yale (Ph.B., 1878), Johns Hopkins (Ph.D., 1881). He taught at Bryn Mawr (1885–91) and at Columbia (1891–1928), where...

Bridges, Calvin Blackman

(Encyclopedia)Bridges, Calvin Blackman, 1889–1938, American geneticist, b. Schuyler Falls, N.Y., grad. Columbia (B.S., 1912; Ph.D., 1916). In his research he collaborated with T. H. Morgan, A. H. Sturtevant, and ...

muscular dystrophy

(Encyclopedia)muscular dystrophy dĭsˈtrōfē [key], any of several inherited diseases characterized by progressive wasting of the skeletal muscles. There are five main forms of the disease. They are classified ac...

Blakeslee, Albert Francis

(Encyclopedia)Blakeslee, Albert Francis, 1874–1954, American botanist, b. Genesee, New York. He received his Ph.D. at Harvard (1904) and was a member of the faculty until 1907. After several years as professor at...

genetics

(Encyclopedia)genetics, scientific study of the mechanism of heredity. While Gregor Mendel first presented his findings on the statistical laws governing the transmission of certain traits from generation to genera...

Morgan, Thomas Hunt

(Encyclopedia)Morgan, Thomas Hunt, 1866–1945, American zoologist, b. Lexington, Ky., Ph.D. Johns Hopkins, 1890. He was professor of experimental zoology at Columbia (1904–28) and from 1928 was director of the l...

sperm

(Encyclopedia)sperm or spermatozoon spûrˌmətəzōˈən, –zōˈŏn [key], in biology, the male gamete (sex cell), corresponding to the female ovum in organisms that reproduce sexually. In higher animals the spe...

Alzheimer's disease

(Encyclopedia)Alzheimer's disease ălsˈhīˌmərz, ôls– [key], degenerative disease of nerve cells in the cerebral cortex that leads to atrophy of the brain and senile dementia and, ultimately, death. The disea...

aggression

(Encyclopedia)aggression, a form of behavior characterized by physical or verbal attack. It may appear either appropriate and self-protective, even constructive, as in healthy self-assertiveness, or inappropriate a...

Browse by Subject