Necrosis and apoptosis are differentiated by their causes, with necrosis being the accidental result of interactions with pathogens and apoptosis being the product of a programmed cell mechanism. These are the two major types of cell death in living, multicellular organisms. Despite this customary dichotomy, research indicates that the distinction between these two types of cell death are not as clear as was once thought.Continue Reading
Necrosis results from the release of toxins from pathogens or other trauma to cells, sufficient to cause cell death. In general this cell death is not a purposeful effect of the pathogen. It is a side effect of its digestive processes. Somewhat confusingly, patches of dead tissue are identified as necroses, even when the cause of the cell death is unknown.
Apoptosis is a vital and regular part of overall organism function and is the programmed death of cells via the cells' own chemical processes. This occurs throughout the body and is necessary to make way for replacement cells as the old ones wear out. It also occurs in response to certain pathogens, particularly viruses, as a cell which destroys itself does not propagate the virus. Apoptosis begins with the destruction of the interior structures of the cell, often followed by a rupture of the membrane and absorption of its constituents by nearby cells. Sometimes, however, as in the outermost layers of the skin, the dead cells do not rupture but stay in place and continue to serve a function after death.Learn more about Cells
Certain white blood cells resemble unicellular organisms, particularly amoebas, in that they are free of set tissue structures, are capable of moving themselves via extension of pseudopods, and they destroy pathogens and particles by engulfing them, according to Boundless.com. These white blood cells are known as phagocytes. In the blood, these are generally monocytes and neutrophils. In other tissues, these cell types become macrophages, which are even more amoeba-like.Full Answer >
Dark urine is typically the result of inadequate fluid intake, explains WebMD, while incontinence is the product of several factors. These include an overactive bladder, excessive fluid intake, and irritation of the bladder, notes Mayo Clinic.Full Answer >
Primary endosymbiosis is the hypothesis that the first eukaryotic cells began as a result of the coming together of different types of microbes. Animal cells all contain mitochondria, and these organelles show many signs of having once been free-living prokaryotes that were taken up by early nucleated cells.Full Answer >
When cells undergo meiosis, the main result is the creation of sex cells called gametes. Male organisms produce sperm via the process of meiosis, while female organisms produce ova cells. In some species, individuals possess the capability of producing both sperm and egg cells via meiosis.Full Answer >