from The Century Dictionary.
- noun In embryology, the series of active changes which take place in the nucleus of a living cell in the process of division. Also written
from the GNU version of the Collaborative International Dictionary of English.
- noun (Biol.) The indirect division of cells in which, prior to division of the cell protoplasm, complicated changes take place in the nucleus, attended with movement of the nuclear fibrils; -- opposed to
karyostenosis. The nucleus becomes enlarged and convoluted, and finally the threads are separated into two groups which ultimately become disconnected and constitute the daughter nuclei. Called also mitosis. See Cell development, under cell.
- noun The changes that occur in the nucleus of a cell, especially movements of the chromosomes, in the process of cell division.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun biology The process of change that takes place during the
divisionof a cell nucleusat mitosisor meiosis.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- noun organic process consisting of the division of the nucleus of a cell during mitosis or meiosis
Sorry, no etymologies found.
"karyokinesis," and is found throughout the higher animals as well as plants.
Indirect division or karyokinesis (karyomitosis) has been observed in all the tissuesgenerative cells, epithelial tissue, connective tissue, muscular tissue, and nerve tissue.
Association in 1912, argued that all the main characteristics of living matter, such as assimilation and disassimilation, growth and reproduction, spontaneous and amoeboid movement, osmotic pressure, karyokinesis, etc., were equally apparent in the non-living; therefore he concluded that life is only one of the many chemical reactions, and that it is not improbable that it will yet be produced by chemical synthesis in the laboratory.
Lastly, with respect to karyokinesis, although it is true that the microscope has in comparatively recent years displayed this apparently important distinction between unicellular and multicellular organisms, two considerations have here to be supplied.
As a matter of fact, in many cases of tissue-formation karyokinesis has not hitherto been detected.
Here, then (Fig. 29), we see the complex processes of karyokinesis in the first two stages of egg-cell division.
Fertilization having been thus effected by fusion of the male and female pronuclei into a single (or new) nucleus, this latter body proceeds to exhibit complicated processes of karyokinesis, which, as before shown, are preliminary to nuclear division in the case of egg-cells.
All this, it will be noticed, is a case of cell-multiplication, which differs from that which takes place in the unicellular organisms only in its being _invariably_ preceded (as far as we know) by karyokinesis, and in the resulting cells being all confined within a common envelope, and so in not being free to separate.
As in the case of sexual propagation, so in that of karyokinesis, processes which are common to all the Metazoa are not wholly without their foreshadowings in the
It is needless to say that I refer to the phenomena of karyokinesis.