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The freshwater alga Spirogyra. Spirogyra can reproduce both sexually and asexually. [9] In vegetative reproduction, fragmentation takes place, and Spirogyra simply undergoes intercalary cell division to extend the length of the new filaments. [10] Sexual reproduction is of two types:
The Zygnemataceae are cosmopolitan, but though all generally occur in the same types of habitats, Mougeotia, Spirogyra, and Zygnema are by far the most common; in one study across North America, [3] 95% of the Zygnemataceae collected were in these three genera. Classification and identification is primarily by the morphology of the conjugation ...
Sexual reproduction in Zygnematales takes place through a process called conjugation. [4] Here filaments of opposite gender line up, and tubes form between corresponding cells. The male cells then become amoeboid and crawl across, or sometimes both cells crawl into the tube.
The Zygnematophyceae are able to reproduce both asexually and sexually. Asexual reproduction takes place via fragmentation, cell division, akinete formation, or parthenospores. [7] Sexual reproduction in the Zygnematophyceae takes place through a process called conjugation. [13]
Fragmentation in multicellular or colonial organisms is a form of asexual reproduction or cloning, where an organism is split into fragments upon maturation and the split part becomes the new individual. The organism may develop specific organs or zones to shed or be easily broken off.
Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the full set of genes of their single parent and thus the newly created individual is genetically and ...
In plants both phases are multicellular: the haploid sexual phase – the gametophyte – alternates with a diploid asexual phase – the sporophyte. A mature sporophyte produces haploid spores by meiosis, a process which reduces the number of chromosomes to half, from two sets to one. The resulting haploid spores germinate and grow into ...
The Zygnematophyceae, formerly known as the Conjugatophyceae, generally possess two fairly elaborate chloroplasts in each cell, rather than many discoid ones. They reproduce asexually by the development of a septum between the two cell-halves or semi-cells (in unicellular forms, each daughter-cell develops the other semi-cell afresh) and sexually by conjugation, or the fusion of the entire ...