- 1. SYN: reproduction (1). 2. A discrete stage in succession of descent; e.g., father, son, and grandson are three generations. [L. generatio, fr. genero, pp. -atus, to beget]- asexual g. reproduction by fission, gemmation, or in any other way without union of the male and female cell, or conjugation. SEE ALSO: parthenogenesis. SYN: heterogenesis (2), nonsexual g..- filial g. (F) the offspring of a genetically specified mating : first filial g. (symbol F1), the offspring of parents of contrasting genotypes; second filial g. (F2), the offspring of two F1 individuals; third filial g. (F3), fourth filial g. (F4), etc., the offspring in succeeding generations of continued inbreeding of F1 descendents.- nonsexual g. SYN: asexual g..- parental g. (P1) the parents of a mating, commonly experimental, involving contrasting genotypes; the original mating of a genetic experiment; parents of the F1 g..- sexual g. reproduction by conjugation, or the union of male and female cells, as opposed to asexual g..- skipped g. a phenomenon of pedigrees in which a gene is transmitted from one affected person to another through a phenotypically unaffected person, as by recessivity (especially for X-linked traits), epistasis, variable expressivity, or absence of an environmental challenge such as a toxin. Except at a crass phenotypic level ( e.g., clinical or commercial) this term becomes progressively less useful as the mechanisms are elucidated.- spontaneous g. the false concept according to which living matter can arise by the vitalization of nonliving matter. SEE ALSO: biogenesis. SYN: heterogenesis (3).
* * *gen·er·a·tion .jen-ə-'rā-shən n1 a) a body of living beings constituting a single step in the line of descent from an ancestorb) a group of individuals born and living contemporaneously2) the average span of time between the birth of parents and that of their offspring3) the action or process of producing offspring: PROCREATIONgen·er·a·tion·al -shnəl, -shən-əl adj
* * *gen·er·a·tion (jen″ər-aґshən) [L. generatio] 1. reproduction (def. 1). 2. a class composed of all individuals removed by the same number of successive ancestors from a common predecessor, or occupying positions on the same level in a pedigree chart. 3. in pharmacology, a subgroup of a larger class of agents that share a certain characteristic and usually were developed around the same time as each other.
Medical dictionary. 2011.