Search results
Results From The WOW.Com Content Network
In trilete spores, each spore shows three narrow lines radiating from a center pole. [8] This shows that four spores shared a common origin and were initially in contact with each other forming a tetrahedron. [3] A wider aperture in the shape of a groove may be termed a colpus. [8] The number of colpi distinguishes major groups of plants.
Dipicolinic acid is a spore-specific chemical that appears to help in the ability for endospores to maintain dormancy. This chemical accounts for up to 10% of the spore's dry weight. [3] Endospores can survive without nutrients. They are resistant to ultraviolet radiation, desiccation, high temperature, extreme freezing and chemical disinfectants.
In meiotic sporogenesis, a diploid spore mother cell within the sporangium undergoes meiosis, producing a tetrad of haploid spores. In organisms that are heterosporous, two types of spores occur: Microsporangia produce male microspores, and megasporangia produce female megaspores. In megasporogenesis, often three of the four spores degenerate ...
The wrong decision can be catastrophic: a vegetative cell will die if the conditions are too harsh, while bacteria forming spores in an environment which is conducive to vegetative growth will be out competed. [3] In short, initiation of sporulation is a very tightly regulated network with numerous checkpoints for efficient control. [citation ...
C. perfringens can proliferate in foods that are improperly stored due to the spore's ability to survive normal cooking temperatures. The type A toxin of C. perfringens, also known as the CPA is responsible for food poisoning. [46] Clostridium perfringens is the most common bacterial agent for gas gangrene. [47]
The formation of resting spores is product of two acytokinetic divisions of the parent cell, [5] wherein the cytoplasm of the daughter cells is shared. The resting spores produced may be either exogeneous (mature spore has no contact with parent cell), endogenous (completely enclosed within the parent cell), or semi-endogenous (only the ...
It can be composed of a single cell or can be multicellular. Virtually all plants , fungi , and many other groups form sporangia at some point in their life cycle . Sporangia can produce spores by mitosis , but in land plants and many fungi, sporangia produce genetically distinct haploid spores by meiosis .
A diagram of C. tetani showing the bacterium alone, with a spore being produced, and the spore alone. Clostridium tetani is a rod-shaped, Gram-positive bacterium, typically up to 0.5 μm wide and 2.5 μm long. [1] It is motile by way of various flagella that surround its body. [1] C. tetani cannot grow in the presence of oxygen. [1]