Search results
Results from the WOW.Com Content Network
In plants, spores are usually haploid and unicellular and are produced by meiosis in the sporangium of a diploid sporophyte. In some rare cases, a diploid spore is also produced in some algae, or fungi. [ 6 ]
The sporangium forms on the sporangiophore and contains haploid nuclei and cytoplasm. [3] Spores are formed in the sporangiophore by encasing each haploid nucleus and cytoplasm in a tough outer membrane. During asexual reproduction, these spores are dispersed via wind and germinate into haploid hyphae. [4]
In meiotic sporogenesis, a diploid spore mother cell within the sporangium undergoes meiosis, producing a tetrad of haploid spores. In organisms that are heterosporous, two types of spores occur: Microsporangia produce male microspores, and megasporangia produce female megaspores. In megasporogenesis, often three of the four spores degenerate ...
The diploid nuclei of blastospores can undergo meiosis, including recombination, to form haploid basidiospores that can be dispersed. [234] This process is referred to as monokaryotic fruiting. This process requires a gene called DMC1 , which is a conserved homologue of genes recA in bacteria and RAD51 in eukaryotes, that mediates homologous ...
Haploid spores germinate to form swarm cells or myxamoebae. These fuse in a process referred to as plasmogamy and karyogamy to form a diploid zygote. The zygote develops into a plasmodium, and the mature plasmodium produces, depending on the species, one to many fruiting bodies containing haploid spores.
Diagram showing the alternation of generations between a diploid sporophyte (bottom) and a haploid gametophyte (top) A sporophyte (/ ˈ s p ɔːr. ə ˌ f aɪ t /) is the diploid multicellular stage in the life cycle of a plant or alga which produces asexual spores. This stage alternates with a multicellular haploid gametophyte phase.
Meiosis occurs during spore development, resulting in haploid dormant spores. Upon exposure to moist nutrient conditions, the spores develop into amoebae, or, in aqueous suspension, into flagellates. The life cycle is completed when haploid amoebae of different mating types fuse to form a diploid zygote that then develops by growth and nuclear ...
Bryophytes reproduce sexually, but the larger and commonly-seen organisms are haploid and produce gametes. The gametes fuse to form a zygote which develops into a sporangium, which in turn produces haploid spores. The diploid stage is relatively small and short-lived compared to the haploid stage, i.e. haploid dominance. The advantage of ...