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Subterminal endospores are those between these two extremes, usually seen far enough towards the poles but close enough to the center so as not to be considered either terminal or central. Lateral endospores are seen occasionally. Examples of bacteria having terminal endospores include Clostridium tetani, the pathogen that causes the disease ...
B. subtilis can divide symmetrically to make two daughter cells (binary fission), or asymmetrically, producing a single endospore that is resistant to environmental factors such as heat, desiccation, radiation and chemical insult which can persist in the environment for long periods of time. The endospore is formed at times of nutritional ...
Endospores can last for decades in multiple hard conditions, such as drying and freezing. This is because the DNA inside the endospore can survive over a long period. Most bacteria are unable to form endospores due to their high resistance, but some common species are the genera Bacillus ( over 100 species) and Clostridium (over 160 species). [2]
Perhaps the best known bacterial adaptation to stress is the formation of endospores. Endospores are bacterial survival structures that are highly resistant to many different types of chemical and environmental stresses and therefore enable the survival of bacteria in environments that would be lethal for these cells in their normal vegetative ...
Bacillus can reduce themselves to oval endospores and can remain in this dormant state for years. The endospore of one species from Morocco is reported to have survived being heated to 420 °C. [2] Endospore formation is usually triggered by a lack of nutrients: the bacterium divides within its cell wall, and one side then engulfs the other.
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]
Two gametes fuse to form a zygote, which develops into a new sporophyte. This cycle is known as alternation of generations . The spores of seed plants are produced internally, and the megaspores (formed within the ovules) and the microspores are involved in the formation of more complex structures that form the dispersal units, the seeds and ...
There is debate as to whether endospory or heterospory evolved first. Some debate centers upon the requirement of endospory to develop before heterospory. [2] Endospory is assumed to follow heterospory but it has been suggested that without endospory, early plant species dependency on water fertilization and environmental impacts on gametophytic gene expression would have reduced the chances ...