Crossword clues for segmentation
Longman Dictionary of Contemporary English
The Collaborative International Dictionary
Segmentation \Seg`men*ta"tion\, n. The act or process of dividing into segments; specifically (Biol.), a self-division into segments as a result of growth; cell cleavage; cell multiplication; endogenous cell formation.
Segmentation cavity (Biol.), the cavity formed by the arrangement of the cells in segmentation or cleavage of the ovum; the cavity of the blastosphere. In the gastrula stage, the segmentation cavity in which the mesoblast is formed lies between the entoblast and ectoblast. See Illust. of Invagination.
Segmentation nucleus (Biol.), the body formed by fusion of the male and female pronucleus in an impregnated ovum. See the Note under Pronucleus.
Segmentation of the ovum, or Egg cleavage (Biol.), the process by which the embryos of all the higher plants and animals are derived from the germ cell. In the simplest case, that of small ova destitute of food yolk, the ovum or egg divides into two similar halves or segments (blastomeres), each of these again divides into two, and so on, thus giving rise to a mass of cells (mulberry mass, or morula), all equal and similar, from the growth and development of which the future animal is to be formed. This constitutes regular segmentation. Quite frequently, however, the equality and regularity of cleavage is interfered with by the presence of food yolk, from which results unequal segmentation. See Holoblastic, Meroblastic, Alecithal, Centrolecithal, Ectolecithal, and Ovum.
Segmentation sphere (Biol.), the blastosphere, or morula. See Morula.
Douglas Harper's Etymology Dictionary
1650s, "a cutting in small pieces;" 1851 of cells, from segment (v.) + -ation.
Wiktionary
n. 1 The act or an instance of dividing into segments. 2 The state of being divided into segments.
WordNet
n. (embryology) the repeated division of a fertilised ovum [syn: cleavage]
the act of dividing or partitioning; separation by the creation of a boundary that divides or keeps apart [syn: division, partition, partitioning, sectionalization, sectionalisation]
Wikipedia
Segmentation may mean:
- Market segmentation, in economics and marketing
Biology
- Segmentation (biology), in morphology, a series of semi-repetitive segments; in developmental biology, a process of morphogenesis that divides a metazoan body into a series of semi-repetitive segments
Computing
- Packet segmentation, the process of dividing a data packet into smaller units for transmission over a data communications network.
- Memory segmentation, the division of computer memory into segments
- Network segmentation, the splitting of a computer network into subnetworks, each being a network segment or network layer
- Image segmentation, the partitioning of a digital image into two or more regions
- In natural language processing:
- Speech segmentation, the identification of word boundaries in speech
- Text segmentation, the identification of lexical units in writing systems
Physiology
- Segmentation contractions (or movements), a type of gastric motility
thumb|125px |right| Vertebrates have a segmented vertebral column and brain.
Segmentation in biology refers to the division of some animal and plant body plans into a series of repetitive segments. This article focuses on the segmentation of animal body plans, specifically using the examples of the phyla Arthropoda, Chordata, and Annelida. These three phyla form segments by using a “growth zone” to direct and define the segments. While all three have a generally segmented body plan and use a “growth zone,” they use different mechanisms for generating this patterning. Even within these phyla, different organisms have different mechanisms for segmenting the body. Segmentation of the body plan is important for allowing free movement and development of certain body parts. It also allows for regeneration in specific individuals.
Usage examples of "segmentation".
Without entering into details it may be mentioned that in the mosses it proceeds both in the archegonium and antheridium by the segmentation of an apical cell, while this is not the case in the liverworts.
Our segmentation would seem to weaken here but not if we gaze carefully into the artful enate process taking place.
The chordates are one of three segmented phyla — segmentation involving a division of the body structure into similar sections, as a train is divided into separate coaches.
Still later, there will be market segmentation not simply along occupational lines, but along socio-economic and psycho-social lines as well.
The clearest evidence of segmentation in the adult human is the repeated vertebrae of the spinal cord (one to each segment) and the repeating line of ribs attached to twelve of them.
The nervous system also shows the existence of segmentation, and does so most clearly in the repeated and regular emergence of pairs of spinal nerves from between vertebrae all down the spinal column.