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Pteridophytes (ferns and lycophytes) are free-sporing vascular plants that have a life cycle with alternating, free-living gametophyte and sporophyte phases that are independent at maturity. The body of the sporophyte is well differentiated into roots, stem and leaves. The root system is always adventitious. The stem is either underground or ...
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 ...
In 2016, the Pteridophyte Phylogeny Group divided order Polypodiales into six suborders. Pteridaceae is the sole family in suborder Pteridiineae, with 52 genera. The suborder has the same circumscription as Smith et al. used for the family. The phylogenetic relationship between these six suborders is shown in this cladogram: [2]
Alternation of generations is defined as the alternation of multicellular diploid and haploid forms in the organism's life cycle, regardless of whether these forms are free-living. [6] In some species, such as the alga Ulva lactuca , the diploid and haploid forms are indeed both free-living independent organisms, essentially identical in ...
Normal asexual reproduction of plants, such as propagation from cuttings or leaves, has never been considered to be apomixis. In contrast to parthenocarpy , which involves seedless fruit formation without fertilization, apomictic fruits have viable seeds containing a proper embryo, with asexual origin.
A prothallus, or prothallium, (from Latin pro = forwards and Greek θαλλος (thallos) = twig) is usually the gametophyte stage in the life of a fern or other pteridophyte. Occasionally the term is also used to describe the young gametophyte of a liverwort or peat moss as well. In lichens it refers to the region of the thallus that is free ...
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 ...
Zoidogamy is a type of plant reproduction in which male gametes (antherozoids) swim in a path of water to the female gametes (archegonium).Zoidogamy is found in algae, bryophytes, pteridophytes, and some gymnosperms (others use siphonogamy).