Search results
Results From The WOW.Com Content Network
[8] Common antibacterial agents that work by destroying vegetative cell walls do not affect endospores. Endospores are commonly found in soil and water, where they may survive for long periods of time. A variety of different microorganisms form "spores" or "cysts", but the endospores of low G+C gram-positive bacteria are by far the most ...
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 ...
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]
Spores have been found in microfossils dating back to the mid-late Ordovician period. [3] Two hypothesized initial functions of spores relate to whether they appeared before or after land plants. The heavily studied hypothesis is that spores were an adaptation of early land plant species, such as embryophytes , that allowed for plants to easily ...
Reproductive spores are generally the result of cell division, most commonly meiosis (e.g. in plant sporophytes). Sporic meiosis is needed to complete the sexual life cycle of the organisms using it. In some cases, sporogenesis occurs via mitosis (e.g. in some fungi and algae). Mitotic sporogenesis is a form of asexual reproduction.
This species is commonly found in the upper layers of the soil and B. subtilis is thought to be a normal gut commensal in humans. A 2009 study compared the density of spores found in soil (about 10 6 spores per gram) to that found in human feces (about 10 4 spores per gram).
Actinomyces species may form endospores, and while individual bacteria are rod-shaped, Actinomyces colonies form fungus-like branched networks of hyphae. [3] The aspect of these colonies initially led to the incorrect assumption that the organism was a fungus and to the name Actinomyces, "ray fungus" (from Greek actis, ray or beam, and mykes ...
The heliobacteria are phototrophic: they convert light energy into chemical energy using a type I reaction center. [6] [7] The primary pigment involved is bacteriochlorophyll g, which is unique to the group and has a unique absorption spectrum; this gives the heliobacteria their own environmental niche. [5]