| single-celled colonial algae occurring in soil and on moist rocks and vegetation and also as a slime or scum on ponds and stagnant waters |
| corresponding in function, but not evolved from corresponding organs, as the wings of a bee and those of a hummingbird |
organogenesis or·gan·o·gen·e·sis (ôr'gə-nō-jěn'ĭ-sĭs, ôr-gān'ə-)
n.
The formation and development of the organs of living things. Also called organogeny.
organogenesis
in embryology, the series of organized integrated processes that transforms an amorphous mass of cells into a complete organ in the developing embryo. The cells of an organ-forming region undergo differential development and movement to form an organ primordium, or anlage. Organogenesis continues until the definitive characteristics of the organ are achieved. Concurrent with this process is histogenesis; the result of both processes is a structurally and functionally complete organ. The accomplishment of organogenesis ends the period during which the developing organism is called an embryo and begins the period in which the organism is called a fetus. See also histogenesis.
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