That phase of prenatal development involved in establishment of the characteristic configuration of the embryonic body; in humans, e. is usually regarded as extending from the end of the second week, when the embryonic disk is formed, to the end of the eighth week, after which the conceptus is usually spoken of as a fetus. [embryo- + G. genesis, origin]
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em·bryo·gen·e·sis .em-brē-ō-'jen-ə-səs n, pl -e·ses -.sēz the formation and development of the embryo
em·bryo·ge·net·ic -jə-'net-ik adj
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em·bryo·gen·e·sis (em″bre-o-jenґə-sis) [embryo + genesis] 1. the formation of an embryo. 2. the development of a new individual by means of sexual reproduction, that is, from a zygote; called also embryogeny and embryony.Medical dictionary. 2011.