Most spores generated by fungi serve two main purposes: reproduction through dispersal and survival via dormancy. Fungal spores can be single-celled or multicelluar.
They come in a variety of colors, shapes, and sizes depending on the species. Fungal spores can be asexual or sexual. Asexual spores, such as sporangiospores, are produced and held within structures called sporangia. Other asexual spores, such as conidia, are produced on filamentous structures called hyphae. Sexual spores include ascospores, basidiospores, and zygospores.
Most fungi rely on the wind to disperse spores to areas where they can germinate successfully. The spores can be actively ejected from reproductive structures ballistospores or can be released without being actively ejected statismospores. Once in the air, the spores are carried by the wind to other locations. Alternation of generations is common among fungi.
Sometimes environmental conditions are such that it is necessary that fungal spores go dormant. Germination after periods of dormancy in some fungi can be triggered by factors including temperature, moisture levels, and the numbers of other spores in an area. Dormancy allows fungi to survive under stressful conditions. Like algae and fungi, plants also exhibit alternation of generations. Plants without seeds, such as ferns and mosses, develop from spores. Spores are produced within sporangia and are released into the environment.
The primary phase of the plant life cycle for non-vascular plants , such as mosses , is the gametophyte generation sexual phase. The gametophyte phase consists of green mossy vegetation, while the sporophtye phase nonsexual phase consists of elongated stalks with spores enclosed within sporangia located at the tip of the stalks.
In vascular plants that do not produce seeds, such as ferns , the sporophtye and gametophyte generations are independent. The fern leaf or frond represents the mature diploid sporophyte, while the sporangia on the underside of the fronds produce spores that develop into the haploid gametophyte. In flowering plants angiosperms and nonflowering seed-bearing plants, the gametophyte generation is totally dependent upon the dominant sporophtye generation for survival.
In angiosperms , the flower produces both male microspores and female megaspores. The male microspores are contained within pollen and the female megaspores are produced within the flower ovary. Upon pollination, the microspores and megaspores unite to form seeds, while the ovary develops into fruit. Slime molds are protists that are similar to both protozoans and fungi. They are found living in moist soils among decaying leaves feeding on soil microbes.
Both plasmodial slime molds and cellular slime molds produce spores that sit atop reproductive stalks or fruiting bodies sporangia.
The spores can be transported in the environment by wind or by attaching to animals. Once placed in a suitable environment, the spores germinate forming new slime molds. Sporozoans are protozoan parasites that do not have locomotive structures flagella, cilia, pseudopodia, etc.
Sporozoans are pathogens that infect animals and are capable of producing spores. Many sporozoans can alternate between sexual and asexual reproduction in their life cycles. Actively scan device characteristics for identification.
Use precise geolocation data. Select personalised content. Create a personalised content profile. Measure ad performance. Select basic ads. Create a personalised ads profile. Select personalised ads. Apply market research to generate audience insights. Measure content performance. Develop and improve products. List of Partners vendors. All forms of asexual reproduction involve a separation of parts from the original plant. This form of reproduction allows asexual plants, when conditions are right, to reproduce rapidly and in large amounts.
Asexual reproduction helps plants to survive in all types of environments. For spore-producing plants, the fertilization process occurs after, rather than before, spore dispersal.
When the air outside becomes dry, pressure builds up inside the plant. The pressure then forces the plant to eject thousands of small spore cells into the air.
Spores can survive very harsh conditions and, since they contain no food matter in them, most predators will not eat them. Once the spore lands, if conditions are right, the gametophyte phase begins. To provoke the gametophyte phase, spores must land in warm, moist and shaded areas. Each spore has a small chance of landing in an ideal spot, which is why spore-bearing plants eject hundreds of spores in hopes that some will land in suitable environs, but only about 1 percent survive the process.
The gametophyte phase begins when the spore splits, forming two genetically identical cells that fuse together to grow into a small, heart-shaped structure called a prothallus. The prothallus germinates, or grows, several root-like hairs called rhizoids to secure itself to the ground.
After several weeks of growth, but the male and female reproductive organs develop from the prothallus. The female organs produce small egg cells, ova, while the male organs produce sperm. To begin the fertilization process requires rain. Once it begins to rain, the sperm swims down the long neck of the prothallus to its base, where it finds the ova. As in mammal reproduction, the sperm fuses with the egg to produce an embryo.
The embryo grows into a new spore producing plant. Once fully developed, this new plant again ejects its spores and the entire cycle begins again.
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