Crossword clues for morula
The Collaborative International Dictionary
Morula \Mor"u*la\, n.; pl. Morul[ae]. [NL., dim. of L. morum a mulberry.] (Biol.) The sphere or globular mass of cells (blastomeres), formed by the clevage of the ovum or egg in the first stages of its development; -- called also mulberry mass, segmentation sphere, and blastosphere. See Segmentation.
Wiktionary
n. (context biology English) A spherical mass of blastomeres that forms following the splitting of a zygote; it becomes the blastula.
WordNet
n. a solid mass of blastomeres that forms when the zygote splits; develops into the blastula
[also: morulae (pl)]
Wikipedia
A morula ( Latin, morus: mulberry) is an early stage embryo consisting of cells (called blastomeres) in a solid ball contained within the zona pellucida.
A morula is distinct from a blastocyst in that a morula (3–4 days post fertilization) is a 16-cell mass in a spherical shape whereas a blastocyst (4–5 days post fertilization) has a cavity inside the zona pellucida along with an inner cell mass. A morula, if untouched and allowed to remain implanted, will eventually develop into a blastocyst.
The morula is produced by a series of cleavage divisions of the early embryo, starting with the single-celled zygote. Once the embryo has divided into 16 cells, it begins to resemble a mulberry, hence the name morula ( Latin, morus: mulberry). Within a few days after fertilization, cells on the outer part of the morula become bound tightly together with the formation of desmosomes and gap junctions, becoming nearly indistinguishable. This process is known as compaction. A cavity forms inside the morula, by the active transport of sodium ions from trophoblast cells and osmosis of water. This results in a hollow ball of cells known as the blastocyst. The blastocyst's outer cells will become the first embryonic epithelium (the trophectoderm). Some cells, however, will remain trapped in the interior and will become the inner cell mass (ICM), and are pluripotent. In mammals (except monotremes), the ICM will ultimately form the "embryo proper", while the trophectoderm will form the placenta and extra-embryonic tissues. However, reptiles have a different ICM. The stages are prolonged and divided in 4 parts.
Morula is a genus of small, predatory sea snails, marine gastropod mollusks in the family Muricidae, the murex snails or rock snails.
Usage examples of "morula".
Arthur, would induce the fertilized ovum to develop beyond the morula stage.
They lost the spoor on the third day in the rain, but a dozen times in the years since then, Flynn had followed and lost those double furrows, and once, through his binoculars, he had seen the old bull again, standing dozing beneath a grove of morula trees at a distance of three miles, his eroded old head propped up by the mythical tusks.
They had stalked to within twenty paces of the enormous, ancient beast as he fed on the fruits of a morula tree.
When they went on again, they had not gone more than a mile before they entered a grove of morula trees.
At first it was thought that the enzyme on the acrosome was being inhibited in some fashion and thus the spermatozoon was being prevented from penetrating the zona pellucida—the protective layer of the ovum— but a series of beautiful demonstrations by Russell and Austin at Cambridge proved beyond all doubt that not only could fertilization still take place outside the uterus, but that non-parthogenic cell division could still be induced in vitro at least as far as the morula stage.