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Since sexual reproduction is often more narrowly defined as the fusion of gametes (fertilization), spore formation in plant sporophytes and algae might be considered a form of asexual reproduction (agamogenesis) despite being the result of meiosis and undergoing a reduction in ploidy. However, both events (spore formation and fertilization) are ...
The members of this group are found in aquatic habitats and on decaying wood in moist and damp places or as obligate parasites on plants. The mycelium is aseptate and coenocytic. Asexual reproduction by zoospore or by aplanospore. A zygospore is formed by the fusion of two gametes. Examples are Mucor, Rhizopus, Albugo, Saprolegnia.
The name Zygomycota refers to the zygosporangia characteristically formed by the members of this clade, in which resistant spherical spores are formed during sexual reproduction. Zygos is Greek for "joining" or "a yoke ", referring to the fusion of two hyphal strands which produces these spores, and -mycota is a suffix referring to a division ...
Asexual reproduction in plants occurs in two fundamental forms, vegetative reproduction and agamospermy. [1] Vegetative reproduction involves a vegetative piece of the original plant producing new individuals by budding, tillering , etc. and is distinguished from apomixis , which is a replacement of sexual reproduction, and in some cases ...
Asexual reproduction often occurs continuously. In heterothallic species, sexual reproduction occurs when opposite mating types (designated + and -) come into close proximity, inducing the formation of specialized hyphae called gametangia. The gametangia grow toward each other, then fuse, forming a diploid zygote at the point of fusion.
In asexual reproduction, spores are produced inside a spherical structure, the sporangium. Sporangia are supported by a large apophysate columella atop a long stalk, the sporangiophore. Sporangiophores arise among distinctive, root-like rhizoids. In sexual reproduction, a dark zygospore is produced at the point where two compatible mycelia fuse ...
The asexual cycle includes the formation of spore containing sporangia borne on the top of sporangiophores that may extend 10 to 15 cm above the surface of the fungal colony from which they emerged. The long filamentous sporangiophores respond to divergent environmental signals including light, gravity, wind, chemicals, and adjacent objects.
Sexual reproduction in Glomeromycotina is unknown, although its occurrence is inferred from genomic studies. However, specialized hyphae produce chlamydospore-like spores asexually; these may be borne at terminal (apical) or lateral positions on the hyphae, or intercalary (formed within the hypha, between sub-apical cells). [ 8 ]