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Endospores are resistant to most agents that would normally kill the vegetative cells they formed from. Unlike persister cells, endospores are the result of a morphological differentiation process triggered by nutrient limitation (starvation) in the environment; endosporulation is initiated by quorum sensing within the "starving" population.
Sporogenesis is the production of spores in biology.The term is also used to refer to the process of reproduction via spores. Reproductive spores were found to be formed in eukaryotic organisms, such as plants, algae and fungi, during their normal reproductive life cycle.
The mitosis process in the cells of eukaryotic organisms follows a similar pattern, but with variations in three main details. "Closed" and "open" mitosis can be distinguished on the basis of nuclear envelope remaining intact or breaking down. An intermediate form with partial degradation of the nuclear envelope is called "semiopen" mitosis.
The eukaryotic cell cycle consists of four distinct phases: G 1 phase, S phase (synthesis), G 2 phase (collectively known as interphase) and M phase (mitosis and cytokinesis). M phase is itself composed of two tightly coupled processes: mitosis, in which the cell's nucleus divides, and cytokinesis, in which the cell's cytoplasm and cell membrane divides forming two daughter cells.
Spores produced in a sporic life cycle. Fresh snow partially covers rough-stalked feather-moss ( Brachythecium rutabulum ) , growing on a thinned hybrid black poplar ( Populus x canadensis ) . The last stage of the moss lifecycle is shown, where the sporophytes are visible before dispersion of their spores: the calyptra ( 1 ) is still attached ...
Some genera of Gram-positive bacteria, such as Bacillus, Clostridium, Sporohalobacter, Anaerobacter, and Heliobacterium, can form highly resistant, dormant structures called endospores. [93] Endospores develop within the cytoplasm of the cell; generally, a single endospore develops in each cell. [94]
Spores form a part of the life cycles of a diverse range of organisms such as many bacteria, plants, algae, fungi and some protozoa. In Saccharomyces cerevisiae (Kingdom Fungi), the set of early genes activating sporulation is induced by Ime1 (Inducer of Meiosis 1) and a regulator of middle genes is Ndt80p. [ 4 ]
They allow survival and are not a form of reproduction. [19] Under suitable conditions the spore germinates to produce a viable bacterium. Endospores are formed inside the mother cell, whereas exospores are formed at the end of the mother cell as a bud. [20]