Search results
Results From The WOW.Com Content Network
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.
Rhizopus is a genus of common saprophytic fungi on plants and specialized parasites on animals. They are found in a wide variety of organic substances, including "mature fruits and vegetables", [ 2 ] jellies, syrups, leather, bread, peanuts, and tobacco.
However, both events (spore formation and fertilization) are necessary to complete sexual reproduction in the plant life cycle. Fungi and some algae can also utilize true asexual spore formation, which involves mitosis giving rise to reproductive cells called mitospores that develop into a new organism after dispersal.
Spores are usually haploid and grow into mature haploid individuals through mitotic division of cells (Urediniospores and Teliospores among rusts are dikaryotic). Dikaryotic cells result from the fusion of two haploid gamete cells. Among sporogenic dikaryotic cells, karyogamy (the fusion of the two haploid nuclei) occurs to produce a diploid cell.
The gametophyte is the multicellular structure (plant) that is haploid, containing a single set of chromosomes in each cell. The gametophyte produces male or female gametes (or both), by a process of cell division, called mitosis. In vascular plants with separate gametophytes, female gametophytes are known as mega gametophytes (mega=large, they ...
Rhizopus arrhizus is a fungus of the family Mucoraceae, characterized by sporangiophores that arise from nodes at the point where the rhizoids are formed and by a hemispherical columella. It is the most common cause of mucormycosis in humans and occasionally infects other animals. Rhizopus arrhizus spores contain ribosomes as a spore ...
Rhizopus microsporus lives as a necrotroph where both the fungus (Rhizopus microsporus) and its harbored endobacteria (Paraburkholderia rhizoxinica) form a symbiotic relationship. In order to kill the living cells of its host, the harbored endobacteria secrete rhizoxin, a toxin that inhibits cell mitosis and vegetative production. [13]
The first is that cells of opposite mating type are present together in the same ascus, the sac that contains the tetrad of cells directly produced by a single meiosis, and these cells can mate with each other. The second reason is that haploid cells of one mating type, upon cell division, often produce cells of the opposite mating type with ...