In aquatic species of mucor, where their is high acidity and more sugar-rich substance hypha become septed than septed portion become round in shape and separate from the parent hypha.
These are thin walled asexual spore called oidia. In mucor sexual reproduction takes place by gametangial conjugation. Some species are homothallic conjugation takes place between hypha of same species and heterothallic conjugation occurs between hypha of opposite strain. Sexual reproduction takes place at the end of growing season.
Two hyphae of opposite strain come in contact with each other and develop short outgrowth called protuberance. Accumulation of cytoplasm and nuclei takes place at the protuberance. Then swelling occur in each protuberance which forms progametangium. A septum is formed in each gametangium which separates terminal fertile more nucleated part into gametangium and basal sterile more vacuolated part into suspensor.
Each gametangium work as canoe gamete and fusion of co Eno gametes takes place. Firstly plasmogamy occurs then karyogamy occur which result in the formation of diploid zygote. Zygote enlarges in size and get surrounded by the thick-walled warty structure and change into a zygospore. Zygospore is dark black in colour and has two covering layer. The outer layer is exosporium and the inner layer is endosporium. Zygospore is resting spore, it undergoes resting period.
In return of favourable condition, zygospore starts to germinate. Before germination, it undergoes meiosis cell division and it forms many haploid nuclei of both strains. Among these haploid nuclei, single haploid nucleus remains functional other degenerates.
That single functional haploid nucleus undergoes mitosis cell division and produces many haploid nuclei of same strains. In germination, exosporium gets burst and endosporium come out as germ tube. Germ tube produces germ sporangium at its tip. Inside germ sporangium, their are many haploid spores called germ spores. Germspore comes out by bursting germ sporangium and germinate and develop into new mycelium. Reproduction in Mucor Subject: Biology.
In both sexual and asexual reproduction, fungi produce spores that disperse from the parent organism by either floating on the wind or hitching a ride on an animal.
Fungal spores are smaller and lighter than plant seeds. The giant puffball mushroom bursts open and releases trillions of spores. The huge number of spores released increases the likelihood of landing in an environment that will support growth. The release of fungal spores : The a giant puff ball mushroom releases b a cloud of spores when it reaches maturity. Fungi reproduce asexually by fragmentation, budding, or producing spores.
Fragments of hyphae can grow new colonies. Mycelial fragmentation occurs when a fungal mycelium separates into pieces with each component growing into a separate mycelium.
Somatic cells in yeast form buds. During budding a type of cytokinesis , a bulge forms on the side of the cell, the nucleus divides mitotically, and the bud ultimately detaches itself from the mother cell.
The most common mode of asexual reproduction is through the formation of asexual spores, which are produced by one parent only through mitosis and are genetically identical to that parent. Spores allow fungi to expand their distribution and colonize new environments.
They may be released from the parent thallus, either outside or within a special reproductive sac called a sporangium. Types of fungal reproduction : Fungi may utilize both asexual and sexual stages of reproduction; sexual reproduction often occurs in response to adverse environmental conditions. There are many types of asexual spores. Conidiospores are unicellular or multicellular spores that are released directly from the tip or side of the hypha.
Other asexual spores originate in the fragmentation of a hypha to form single cells that are released as spores; some of these have a thick wall surrounding the fragment. Yet others bud off the vegetative parent cell.
Sporangiospores are produced in a sporangium. Release of spores from a sporangium : This bright field light micrograph shows the release of spores from a sporangium at the end of a hypha called a sporangiophore. The organism depicted is a Mucor sp. Sexual reproduction introduces genetic variation into a population of fungi. In fungi, sexual reproduction often occurs in response to adverse environmental conditions.
Two mating types are produced. When both mating types are present in the same mycelium, it is called homothallic, or self-fertile. Heterothallic mycelia require two different, but compatible, mycelia to reproduce sexually. Although there are many variations in fungal sexual reproduction, all include the following three stages. Finally, meiosis takes place in the gametangia singular, gametangium organs, in which gametes of different mating types are generated. At this stage, spores are disseminated into the environment.
Privacy Policy. Skip to main content. Search for:. Characteristics of Fungi. Characteristics of Fungi Fungi, latin for mushroom, are eukaryotes which are responsible for decomposition and nutrient cycling through the environment.
Learning Objectives Describe the role of fungi in the ecosystem. Key Takeaways Key Points Fungi are more closely related to animals than plants.
Fungi are heterotrophic: they use complex organic compounds as sources of energy and carbon, not photosynthesis. Fungi multiply either asexually, sexually, or both. The majority of fungi produce spores, which are defined as haploid cells that can undergo mitosis to form multicellular, haploid individuals.
Fungi interact with other organisms by either forming beneficial or mutualistic associations mycorrhizae and lichens or by causing serious infections. Key Terms mycorrhiza : a symbiotic association between a fungus and the roots of a vascular plant spore : a reproductive particle, usually a single cell, released by a fungus, alga, or plant that may germinate into another lichen : any of many symbiotic organisms, being associations of fungi and algae; often found as white or yellow patches on old walls, etc.
Ascomycota : a taxonomic division within the kingdom Fungi; those fungi that produce spores in a microscopic sporangium called an ascus heterotrophic : organisms that use complex organic compounds as sources of energy and carbon. Fungi Cell Structure and Function Fungi are unicellular or multicellular thick-cell-walled heterotroph decomposers that eat decaying matter and make tangles of filaments.
Learning Objectives Describe the physical structures associated with fungi. Key Takeaways Key Points Fungal cell walls are rigid and contain complex polysaccharides called chitin adds structural strength and glucans.
Ergosterol is the steroid molecule in the cell membranes that replaces the cholesterol found in animal cell membranes. Fungi can be unicellular, multicellular, or dimorphic, which is when the fungi is unicellular or multicellular depending on environmental conditions.
A hard wall covers these spores, and it develops inside the vegetative cell during unfavourable conditions. In unfavourable conditions, mycelium becomes septate by the accumulation of nuclei and cytoplasm in a certain portion and becomes surrounded by a thick wall called chlamydospores.
This spore then detaches from the mycelium and remains dormant. On favourable conditions, they form a germ tube. When a mycelium grows in a substrate rich in sugar , some small, thin-walled and pearl-like reproductive structures form that detaches out of the vegetative cell as in budding of yeast.
Then oidospores remain dormant for some time and on favourable conditions, it forms a germination tube to form a new vegetative body. In Mucor, the sexual reproduction occurs by the method that is called as Gametangial conjugation, which involves the following steps:. Through these three reproductive methods, a Mucor completes its reproductive phase, and it can cause some serial infections or diseases that can affect the ecological system and human health.
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