- the early developmental stage of an animal, following the morula stage and consisting of a single, spherical layer of cells enclosing a hollow, central cavity.
Origin of blastula
1885–90; < New Latin < Greek blast(ós) bud, sprout + New Latin -ula -ule
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for blastula
The round cluster becomes filled with fluid, and we have a hollow sphere of cells, which I call the blastula.
The hollow sphere which is thus formed is the important stage of the “germinal vesicle,” the blastula, or blastosphere.
Consider its mode of division, and the formation of the blastula, gastrula, and germinal layers.The Biological Problem of To-day
In a blastula showing complete segmentation the blastomeres of the upper hemisphere are the more finely subdivided.A Guide to the Study of Fishes, Volume 1 (of 2)
David Starr Jordan
Our next question concerns the distribution of potentiality, when the embryo is developed further than the blastula stage.
- an early form of an animal embryo that develops from a morula, consisting of a sphere of cells with a central cavityAlso called: blastosphere
C19: New Latin; see blasto-
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for blastula
embryonic state, 1875, Modern Latin, from Greek blastos "sprout, germ" + diminutive ending -ula.
Online Etymology Dictionary, © 2010 Douglas Harper
- An early embryonic form produced by cleavage of a fertilized ovum and consisting of a spherical layer of cells surrounding a fluid-filled cavity.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
- An animal embryo at the stage immediately following the division of the fertilized egg cell, consisting of a ball-shaped layer of cells around a fluid-filled cavity known as a blastocoel. Compare gastrula. See also blastocyst.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
This is the stage of development where embryonic stems cells can be harvested for medical research.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.