Antheridium
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An antheridium is a
haploid Ploidy () is the number of complete sets of chromosomes in a cell (biology), cell, and hence the number of possible alleles for Autosome, autosomal and Pseudoautosomal region, pseudoautosomal genes. Here ''sets of chromosomes'' refers to the num ...
structure or organ producing and containing male
gamete A gamete ( ) is a Ploidy#Haploid and monoploid, haploid cell that fuses with another haploid cell during fertilization in organisms that Sexual reproduction, reproduce sexually. Gametes are an organism's reproductive cells, also referred to as s ...
s (called ''antherozoids'' or
sperm Sperm (: sperm or sperms) is the male reproductive Cell (biology), cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm ...
). The plural form is antheridia, and a structure containing one or more antheridia is called an androecium. The androecium is also the collective term for the
stamen The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...
s of
flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...
s. Antheridia are present in the
gametophyte A gametophyte () is one of the two alternating multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has one set of chromosomes. The gametophyte is the se ...
phase of cryptogams like
bryophyte Bryophytes () are a group of embryophyte, land plants (embryophytes), sometimes treated as a taxonomic Division (taxonomy), division referred to as Bryophyta ''Sensu#Common qualifiers, sensu lato'', that contains three groups of non-vascular pla ...
s and
fern The ferns (Polypodiopsida or Polypodiophyta) are a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. They differ from mosses by being vascular, i.e., having specialized tissue ...
s. Many algae and some
fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...
, for example,
ascomycete Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The def ...
s and water moulds, also have antheridia during their
reproductive The reproductive system of an organism, also known as the genital system, is the biological system made up of all the anatomical organs involved in sexual reproduction. Many non-living substances such as fluids, hormones, and pheromones are al ...
stages. In
gymnosperm The gymnosperms ( ; ) are a group of woody, perennial Seed plant, seed-producing plants, typically lacking the protective outer covering which surrounds the seeds in flowering plants, that include Pinophyta, conifers, cycads, Ginkgo, and gnetoph ...
s and
angiosperm Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed within a fruit ...
s, the male gametophytes have been reduced to pollen grains, and in most of these, the antheridia have been reduced to a single
generative cell Generative may refer to: * Generative art, art that has been created using an autonomous system that is frequently, but not necessarily, implemented using a computer * Generative design, form finding process that can mimic nature’s evolutionary ...
within the pollen grain. During
pollination Pollination is the transfer of pollen from an anther of a plant to the stigma (botany), stigma of a plant, later enabling fertilisation and the production of seeds. Pollinating agents can be animals such as insects, for example bees, beetles or bu ...
, this generative cell divides and gives rise to sperm cells. The female counterpart to the antheridium in cryptogams is the archegonium, and in flowering plants is the
gynoecium Gynoecium (; ; : gynoecia) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl (botany), whorl of a flower; it consists ...
. An antheridium typically consists of sterile cells and spermatogenous tissue. The sterile cells may form a central support structure or surround the spermatogenous tissue as a protective jacket. The spermatogenous cells give rise to spermatids via mitotic
cell division Cell division is the process by which a parent cell (biology), cell divides into two daughter cells. Cell division usually occurs as part of a larger cell cycle in which the cell grows and replicates its chromosome(s) before dividing. In eukar ...
. In some
bryophyte Bryophytes () are a group of embryophyte, land plants (embryophytes), sometimes treated as a taxonomic Division (taxonomy), division referred to as Bryophyta ''Sensu#Common qualifiers, sensu lato'', that contains three groups of non-vascular pla ...
s, the antheridium is borne on an '' antheridiophore'', a stalk-like structure that carries the antheridium at its apex.


Gallery

File:Chara contraria oogon.jpeg,
Oogonium An oogonium (: oogonia) is a small diploid cell which, upon maturation, forms a primordial follicle in a female fetus or the female (haploid or diploid) gametangium of certain thallophytes. In the mammalian fetus Oogonia are formed in large ...
(larger) and antheridium (with red centre) of the alga '' Chara'', produced on the stem of a plant File:Hypnum cupressiforme perichaetialblaetter.jpeg, File:Antheridia polytrichum.jpg, "Moss flowers": each shoot has a cluster of antheridia, i.e., an androecium. File:Marchantia polymorpha male.jpg, Sperm of the liverwort '' Marchantia polymorpha'' are produced on the upper surface of antheridiophores. File:Marchantia antheridium mosbo6.jpg, Cross-sectional micrograph of the antheridial head of ''Marchantia'' sp., showing antheridia containing spermatogenous tissue. File:Equisetum Antheridia.jpg, Antheridium (indicated by the red box) of an ''
Equisetum ''Equisetum'' (; horsetail) is the only living genus in Equisetaceae, a family of vascular plants that reproduce by spores rather than seeds. ''Equisetum'' is a "living fossil", the only living genus of the entire subclass Equisetidae, which ...
'' sp.


See also

*
Hornwort Hornworts are a group of non-vascular Embryophytes (land plants) constituting the division Anthocerotophyta (). The common name refers to the elongated horn-like structure, which is the sporophyte. As in mosses and liverworts, hornworts have a ...
s have antheridia, in some cases arranged within androecia. * Microsporangia produce spores that give rise to male gametophytes.


References


Further reading

* C.Michael Hogan. 2010
''Fern''. Encyclopedia of Earth. National council for Science and the Environment
Washington, DC {{Botany Plant anatomy Plant reproduction he:מורפולוגיה של הצמח - מונחים#איברים בצמחים פרימיטיביים