| cleavage site | A sequence in DNA that can be recognised and cut by a specific restriction enzyme. (12 Dec 1998) |
|---|---|
| cleavage spindle | The spindle formed during the cleavage of a zygote or its blastomeres. (05 Mar 2000) |
| cleavage stage, ovum | The embryo in its earliest stage, lasting from the first mitotic division of the fertilised ovum into two blastomeres to the formation of the morula, a compact mass of blastomeres. (12 Dec 1998) |
| complete cleavage | Cleavage in which the blastomeres are completely separated; the entire egg participates in cell division. Synonym: complete cleavage, total cleavage. (05 Mar 2000) |
| progressive cleavage | In fungi, a type of sporulation in which cleavage planes in the cytoplasm first produce protospores and then sporangiospores in a sporangium. (05 Mar 2000) |
| holoblastic cleavage | Cleavage in which the blastomeres are completely separated; the entire egg participates in cell division. Synonym: complete cleavage, total cleavage. (05 Mar 2000) |
| pudendal cleavage | The cleft between the labia majora. Synonym: rima pudendi, fissura pudendi, pudendal cleavage, pudendal slit, rima vulvae, urogenital cleft, vulvar slit. (05 Mar 2000) |
| hydrolytic cleavage | <chemistry> The splitting of a compound into fragments by the addition of water, the hydroxyl group being incorporated in one fragment and the hydrogen atom in the other. Origin: Gr. Lysis = dissolution (18 Nov 1997) |
| spiral cleavage | <marine biology> Pattern of early cleavage found in molluscs and annelids (both mosaic eggs). The animal pole blastomeres are rotated with respect to those of the vegetal pole. The handedness of the spiral twist is maternally inherited. (18 Nov 1997) |
| subdural cleavage | Originally thought to be a narrow fluid-filled interval between the dural and arachnoid; now known to be an artificial space created by the separation of the arachnoid from the dura as the result of trauma or some ongoing pathologic process; in the healthy state, the arachnoid is attached to the dura and a naturally occurring subdural space is not present. Synonym: spatium subdurale, cavum subdurale, subdural cavity, subdural cleavage, subdural cleft. (05 Mar 2000) |
| superficial cleavage | Meroblastic cleavage with the divisions limited to the peripheral (surface) cytoplasm of a centrolecithal egg. (05 Mar 2000) |
| determinate cleavage | Cleavage resulting in blastomeres each capable of developing only into a particular embryonic structure. (05 Mar 2000) |
| discoidal cleavage | Meroblastic cleavage limited to the small cap (animal pole) of protoplasm of large-yolked eggs, such as the telolecithal eggs of birds. (05 Mar 2000) |
| incomplete cleavage | Incomplete separation of the blastomeres, with the divisions being limited to the nonyolked portion of the egg. Synonym: incomplete cleavage. (05 Mar 2000) |
| indeterminate cleavage | Cleavage resulting in blastomeres of similar developmental potencies, each capable, when isolated, of producing an entire embryonic body. (05 Mar 2000) |