Zona pellucida : Dictionary / Wörterbuch (BEOLINGUS, TU Chemnitz)

English Dictionary: Zona pellucida	by the DICT Development Group
2 results for Zona pellucida
From WordNet (r) 3.0 (2006) [wn]:
zona pellucida n thick membrane around the mammalian ovum; can be penetrated by one sperm in the fertilization process; usually remains around the fertilized egg until it is implanted in the wall of the uterus
From Webster's Revised Unabridged Dictionary (1913) [web1913]:
d8Zona \[d8]Zo"na\, n.; pl. {Zon[91]}. [L., a girdle. See {Zone}.] A zone or band; a layer. {Zona pellucida}. [NL.] (Biol.) (a) The outer transparent layer, or envelope, of the ovum. It is a more or less elastic membrane with radiating stri[91], and corresponds to the cell wall of an ordinary cell. See {Ovum}, and Illust. of {Microscope}. (b) The zona radiata. {Zona radiata} [NL.] (Biol.), a radiately striated membrane situated next the yolk of an ovum, or separated from it by a very delicate membrane only.