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Disease and virology studies can use permanent cells to maintain cell count and accurately quantify the effects of vaccines. [1] Some embryology studies also use permanent cells to avoid harvesting embryonic cells from pregnant animals; since the cells are permanent, they may be harvested at a later age when an animal is fully developed. [4]
Phagocytosis ("cell eating") is the process by which bacteria, dead tissue, or other bits of material visible under the microscope are engulfed by cells. The material makes contact with the cell membrane, which then invaginates. The invagination is pinched off, leaving the engulfed material in the membrane-enclosed vacuole and the cell membrane ...
Labile cells refer to cells that constantly divide by entering and remaining in the cell cycle. [1] These are contrasted with "stable cells" and "permanent cells". An important example of this is in the epithelium of the cornea , where cells divide at the basal level and move upwards, and the topmost cells die and fall off .
In biology, cell theory is a scientific theory first formulated in the mid-nineteenth century, that living organisms are made up of cells, that they are the basic structural/organizational unit of all organisms, and that all cells come from pre-existing cells.
A primitive cell is a unit cell that contains exactly one lattice point. For unit cells generally, lattice points that are shared by n cells are counted as 1 / n of the lattice points contained in each of those cells; so for example a primitive unit cell in three dimensions which has lattice points only at its eight vertices is considered to contain 1 / 8 of each of them. [3]
Vascular tissue is a complex transporting tissue, formed of more than one cell type, found in vascular plants. The primary components of vascular tissue are the xylem and phloem. These two tissues transport fluid and nutrients internally. There are also two meristems associated with vascular tissue: the vascular cambium and the cork cambium.
Say that a crystal structure is described by a unit cell U. Another unit cell S is a supercell of unit cell U, if S is a cell which describes the same crystal, but has a larger volume than cell U. Many methods which use a supercell perturbate it somehow to determine properties which cannot be determined by the initial cell.
Permanent cell cycle withdrawal refers to the forever stoppage in divisions of cells. In organisms, cells do not divide endlessly. [3] Certain mechanisms are present to prevent cells from indefinite division, which is mostly done by programmed failure in DNA synthesis. By adapting the above mechanism, cells are prevented from over dividing.