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A pteridophyte is a vascular plant (with xylem and phloem) that reproduces by means of spores. Because pteridophytes produce neither flowers nor seeds , they are sometimes referred to as " cryptogams ", meaning that their means of reproduction is hidden.
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 ...
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 ...
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 ...
Females of species have the ability to reproduce asexually, without sperm from a male. The process is called parthenogenesis, from the Greek words for “virgin” and “birth.” ...
The production of gemmae is a widespread means of asexual reproduction in both liverworts and mosses. In liverworts such as Marchantia, the flattened plant body or thallus is a haploid gametophyte with gemma cups scattered about its upper surface. The gemma cups are cup-like structures containing gemmae.
Agamospermy, asexual reproduction through seeds, occurs in flowering plants through many different mechanisms [4] and a simple hierarchical classification of the different types is not possible. Consequently, there are almost as many different usages of terminology for apomixis in angiosperms as there are authors on the subject.
In some phyla of fungi, the sporangium plays a role in asexual reproduction, and may play an indirect role in sexual reproduction. 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.