1.
Taxonomy (biology)
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Taxonomy is the science of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. The exact definition of taxonomy varies from source to source, but the core of the remains, the conception, naming. There is some disagreement as to whether biological nomenclature is considered a part of taxonomy, the broadest meaning of taxonomy is used here. The word taxonomy was introduced in 1813 by Candolle, in his Théorie élémentaire de la botanique, the term alpha taxonomy is primarily used today to refer to the discipline of finding, describing, and naming taxa, particularly species. In earlier literature, the term had a different meaning, referring to morphological taxonomy, ideals can, it may be said, never be completely realized. They have, however, a value of acting as permanent stimulants. Some of us please ourselves by thinking we are now groping in a beta taxonomy, turrill thus explicitly excludes from alpha taxonomy various areas of study that he includes within taxonomy as a whole, such as ecology, physiology, genetics, and cytology. He further excludes phylogenetic reconstruction from alpha taxonomy, thus, Ernst Mayr in 1968 defined beta taxonomy as the classification of ranks higher than species. This activity is what the term denotes, it is also referred to as beta taxonomy. How species should be defined in a group of organisms gives rise to practical and theoretical problems that are referred to as the species problem. The scientific work of deciding how to define species has been called microtaxonomy, by extension, macrotaxonomy is the study of groups at higher taxonomic ranks, from subgenus and above only, than species. While some descriptions of taxonomic history attempt to date taxonomy to ancient civilizations, earlier works were primarily descriptive, and focused on plants that were useful in agriculture or medicine. There are a number of stages in scientific thinking. Early taxonomy was based on criteria, the so-called artificial systems. Later came systems based on a complete consideration of the characteristics of taxa, referred to as natural systems, such as those of de Jussieu, de Candolle and Bentham. The publication of Charles Darwins Origin of Species led to new ways of thinking about classification based on evolutionary relationships and this was the concept of phyletic systems, from 1883 onwards. This approach was typified by those of Eichler and Engler, the advent of molecular genetics and statistical methodology allowed the creation of the modern era of phylogenetic systems based on cladistics, rather than morphology alone. Taxonomy has been called the worlds oldest profession, and naming and classifying our surroundings has likely been taking place as long as mankind has been able to communicate
2.
Carl Linnaeus
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Carl Linnaeus, also known after his ennoblement as Carl von Linné, was a Swedish botanist, physician, and zoologist, who formalised the modern system of naming organisms called binomial nomenclature. He is known by the father of modern taxonomy. Many of his writings were in Latin, and his name is rendered in Latin as Carolus Linnæus, Linnaeus was born in the countryside of Småland, in southern Sweden. He received most of his education at Uppsala University. He lived abroad between 1735 and 1738, where he studied and also published a first edition of his Systema Naturae in the Netherlands and he then returned to Sweden, where he became professor of medicine and botany at Uppsala. In the 1740s, he was sent on journeys through Sweden to find and classify plants. In the 1750s and 1760s, he continued to collect and classify animals, plants, and minerals, at the time of his death, he was one of the most acclaimed scientists in Europe. The philosopher Jean-Jacques Rousseau sent him the message, Tell him I know no man on earth. The German writer Johann Wolfgang von Goethe wrote, With the exception of Shakespeare and Spinoza, Swedish author August Strindberg wrote, Linnaeus was in reality a poet who happened to become a naturalist. Among other compliments, Linnaeus has been called Princeps botanicorum, The Pliny of the North and he is also considered as one of the founders of modern ecology. In botany, the abbreviation used to indicate Linnaeus as the authority for species names is L. In older publications, sometimes the abbreviation Linn. is found, Linnæus was born in the village of Råshult in Småland, Sweden, on 23 May 1707. He was the first child of Nicolaus Ingemarsson and Christina Brodersonia and his siblings were Anna Maria Linnæa, Sofia Juliana Linnæa, Samuel Linnæus, and Emerentia Linnæa. One of a line of peasants and priests, Nils was an amateur botanist, a Lutheran minister. Christina was the daughter of the rector of Stenbrohult, Samuel Brodersonius, a year after Linnæus birth, his grandfather Samuel Brodersonius died, and his father Nils became the rector of Stenbrohult. The family moved into the rectory from the curates house, even in his early years, Linnæus seemed to have a liking for plants, flowers in particular. Whenever he was upset, he was given a flower, which calmed him. Nils spent much time in his garden and often showed flowers to Linnaeus, soon Linnæus was given his own patch of earth where he could grow plants
3.
Plato
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Plato was a philosopher in Classical Greece and the founder of the Academy in Athens, the first institution of higher learning in the Western world. He is widely considered the most pivotal figure in the development of philosophy, unlike nearly all of his philosophical contemporaries, Platos entire work is believed to have survived intact for over 2,400 years. Along with his teacher, Socrates, and his most famous student, Aristotle, Plato laid the foundations of Western philosophy. Alfred North Whitehead once noted, the safest general characterization of the European philosophical tradition is that it consists of a series of footnotes to Plato. In addition to being a figure for Western science, philosophy. Friedrich Nietzsche, amongst other scholars, called Christianity, Platonism for the people, Plato was the innovator of the written dialogue and dialectic forms in philosophy, which originate with him. He was not the first thinker or writer to whom the word “philosopher” should be applied, few other authors in the history of Western philosophy approximate him in depth and range, perhaps only Aristotle, Aquinas and Kant would be generally agreed to be of the same rank. Due to a lack of surviving accounts, little is known about Platos early life, the philosopher came from one of the wealthiest and most politically active families in Athens. Ancient sources describe him as a bright though modest boy who excelled in his studies, the exact time and place of Platos birth are unknown, but it is certain that he belonged to an aristocratic and influential family. Based on ancient sources, most modern scholars believe that he was born in Athens or Aegina between 429 and 423 BCE. According to a tradition, reported by Diogenes Laertius, Ariston traced his descent from the king of Athens, Codrus. Platos mother was Perictione, whose family boasted of a relationship with the famous Athenian lawmaker, besides Plato himself, Ariston and Perictione had three other children, these were two sons, Adeimantus and Glaucon, and a daughter Potone, the mother of Speusippus. The brothers Adeimantus and Glaucon are mentioned in the Republic as sons of Ariston, and presumably brothers of Plato, but in a scenario in the Memorabilia, Xenophon confused the issue by presenting a Glaucon much younger than Plato. Then, at twenty-eight, Hermodorus says, went to Euclides in Megara, as Debra Nails argues, The text itself gives no reason to infer that Plato left immediately for Megara and implies the very opposite. Thus, Nails dates Platos birth to 424/423, another legend related that, when Plato was an infant, bees settled on his lips while he was sleeping, an augury of the sweetness of style in which he would discourse about philosophy. Ariston appears to have died in Platos childhood, although the dating of his death is difficult. Perictione then married Pyrilampes, her mothers brother, who had served many times as an ambassador to the Persian court and was a friend of Pericles, Pyrilampes had a son from a previous marriage, Demus, who was famous for his beauty. Perictione gave birth to Pyrilampes second son, Antiphon, the half-brother of Plato and these and other references suggest a considerable amount of family pride and enable us to reconstruct Platos family tree
4.
Aristotle
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Aristotle was an ancient Greek philosopher and scientist born in the city of Stagira, Chalkidice, on the northern periphery of Classical Greece. His father, Nicomachus, died when Aristotle was a child, at seventeen or eighteen years of age, he joined Platos Academy in Athens and remained there until the age of thirty-seven. Shortly after Plato died, Aristotle left Athens and, at the request of Philip II of Macedon, teaching Alexander the Great gave Aristotle many opportunities and an abundance of supplies. He established a library in the Lyceum which aided in the production of many of his hundreds of books and he believed all peoples concepts and all of their knowledge was ultimately based on perception. Aristotles views on natural sciences represent the groundwork underlying many of his works, Aristotles views on physical science profoundly shaped medieval scholarship. Their influence extended from Late Antiquity and the Early Middle Ages into the Renaissance, some of Aristotles zoological observations, such as on the hectocotyl arm of the octopus, were not confirmed or refuted until the 19th century. His works contain the earliest known study of logic, which was incorporated in the late 19th century into modern formal logic. Aristotle was well known among medieval Muslim intellectuals and revered as The First Teacher and his ethics, though always influential, gained renewed interest with the modern advent of virtue ethics. All aspects of Aristotles philosophy continue to be the object of academic study today. Though Aristotle wrote many elegant treatises and dialogues – Cicero described his style as a river of gold – it is thought that only around a third of his original output has survived. Aristotle, whose means the best purpose, was born in 384 BC in Stagira, Chalcidice. His father Nicomachus was the physician to King Amyntas of Macedon. Aristotle was orphaned at a young age, although there is little information on Aristotles childhood, he probably spent some time within the Macedonian palace, making his first connections with the Macedonian monarchy. At the age of seventeen or eighteen, Aristotle moved to Athens to continue his education at Platos Academy and he remained there for nearly twenty years before leaving Athens in 348/47 BC. Aristotle then accompanied Xenocrates to the court of his friend Hermias of Atarneus in Asia Minor, there, he traveled with Theophrastus to the island of Lesbos, where together they researched the botany and zoology of the island. Aristotle married Pythias, either Hermiass adoptive daughter or niece and she bore him a daughter, whom they also named Pythias. Soon after Hermias death, Aristotle was invited by Philip II of Macedon to become the tutor to his son Alexander in 343 BC, Aristotle was appointed as the head of the royal academy of Macedon. During that time he gave not only to Alexander
5.
Kalmia
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Kalmia is a genus of about 8 species of evergreen shrubs from 0. 2–5 m tall, in the family Ericaceae. They are native to North America and Cuba and they grow in acidic soils, with different species in wet acid bog habitats and dry, sandy soils. Kalmia was named by Linnaeus to honour his friend the botanist Pehr Kalm, earlier Mark Catesby saw it during his travels in Carolina, and after his return to England in 1726, imported seeds. The leaves are 2–12 cm long and simple lanceolate, the flowers are white, pink or purple, in corymbs of 10-50, reminiscent of Rhododendron flowers but flatter, with a star-like calyx of five conjoined petals, each flower is 1–3 cm diameter. The fruit is a capsule, which splits to release the numerous small seeds. The foliage is toxic if eaten, with sheep being particularly prone to poisoning, other names for Kalmia, particularly Kalmia angustifolia, are sheep-laurel, lamb-kill, calf-kill, kill-kid, and sheep-poison, which may be written with or without the hyphen. Kid here refers to a goat, not a human child. It has also been called spoonwood because Kalm was told by Dutch settlers of North America that Native Americans made spoons from the wood, given its toxicity, this may be folklore rather than scientific fact. Kalmias are popular garden shrubs, grown for their decorative flowers and they should not be planted where they are accessible to livestock due to the toxicity. Kalmia species are used as food plants by the larvae of some species including Coleophora kalmiella which feeds exclusively on Kalmia. Kalmia angustifolia L. - Sheep-laurel, Lambkill Kalmia buxifolia Gift & Kron - Sandmyrtle Kalmia carolina Small - Carolina Mountain-laurel Kalmia cuneata Michx, - Whitewicky Kalmia ericoides Wright - Cuban Kalmia Kalmia hirsuta Walt. - Hairy Mountain-laurel Kalmia latifolia L. - Mountain-laurel, Lambkill Kalmia microphylla A, - Bog Kalmia, Bog-laurel Kalmia procumbens Gift & Kron - Alpine azalea The related Kalmiopsis is a rare shrub native to the Siskiyou Mountains of southwest Oregon. Jaynes, Richard A.1997, Kalmia, mountain laurel and related species, Timber Press, Portland, Oregon, info about Kalmia latifolia European Kalmia Society A German hybridizer
6.
Stamen
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The stamen is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium, a stamen typically consists of a stalk called the filament and an anther which contains microsporangia. Most commonly anthers are two-lobed and are attached to the filament either at the base or in the area of the anther. The sterile tissue between the lobes is called the connective, a pollen grain develops from a microspore in the microsporangium and contains the male gametophyte. The stamens in a flower are called the androecium. The androecium can consist of as few a one-half stamen as in Canna species or as many as 3,482 stamens which have been counted in Carnegiea gigantea, the androecium in various species of plants forms a great variety of patterns, some of them highly complex. It surrounds the gynoecium and is surrounded by the perianth, a few members of the family Triuridaceae, particularly Lacandonia schismatica, are exceptional in that their gynoecia surround their androecia. Stamen is the Latin word meaning thread, depending on the species of plant, some or all of the stamens in a flower may be attached to the petals or to the floral axis. They also may be free-standing or fused to one another in different ways, including fusion of some. The filaments may be fused and the free, or the filaments free. Rather than there being two locules, one locule of a stamen may fail to develop, or alternatively the two locules may merge late in development to give a single locule, a typical anther contains four microsporangia. The microsporangia form sacs or pockets in the anther, the two separate locules on each side of an anther may fuse into a single locule. Each microsporangium is lined with a tissue layer called the tapetum. These undergo meiosis to form haploid spores, the spores may remain attached to each other in a tetrad or separate after meiosis. Each microspore then divides mitotically to form an immature microgametophyte called a pollen grain, the pollen is eventually released when the anther forms openings. These may consist of longitudinal slits, pores, as in the family, or by valves. More commonly, mature pollen grains separate and are dispensed by wind or water, pollinating insects, pollen of angiosperms must be transported to the stigma, the receptive surface of the carpel, of a compatible flower, for successful pollination to occur. After arriving, the pollen grain typically completes its development and it may grow a pollen tube and undergoing mitosis to produce two sperm nuclei
7.
Ovary (botany)
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In the flowering plants, an ovary is a part of the female reproductive organ of the flower or gynoecium. Specifically, it is the part of the pistil which holds the ovule and is located above or below or at the point of connection with the base of the petals and sepals. The pistil may be made up of one carpel or of several fused carpels, some wind pollinated flowers have much reduced and modified ovaries. A fruit is the ovary or ovaries—together with seeds—from one or more flowers. The fruits of a plant are responsible for dispersing the seeds contain the embryo. In many species, the fruit incorporates some surrounding tissues, or is dispersed with some non-fruit tissues, locules are chambers within the ovary of the flower and fruits. The locules contain the ovules, and may or may not be filled with fruit flesh, depending on the number of locules in the ovary, fruits can be classified as uni-locular, bi-locular, tri-locular or multi-locular. Some plants have septa between the carpels, the number of locules present in a gynoecium may be equal to or less than the number of carpels, the ovules are attached to parts of the interior ovary walls called the placentae. Placental areas occur in various positions, corresponding to parts of the carpels that make up the ovary. An obturator is present in the ovary of some plants, near the micropyle of each ovule and it is an outgrowth of the placenta, important in nourishing and guiding pollen tubes to the micropyle. The ovary of some types of fruit is dehiscent, the ovary wall splits into sections called valves, the terminology of the positions of ovaries is determined by the insertion point, where the other floral parts come together and attach to the surface of the ovary. If the ovary is situated above the point, it is superior, if below. A superior ovary is an attached to the receptacle above the attachment of other floral parts. A superior ovary is found in types of fruits such as true berries, drupes. A flower with this arrangement is described as hypogynous, examples of this ovary type include the legumes. A half-inferior ovary is embedded or surrounded by the receptacle and this occurs in flowers of the Lythraceae family, which includes the Crape Myrtles. Such flowers are termed perigynous or half-epigynous, in some classifications, half-inferior ovaries are not recognized and are instead grouped with either the superior or inferior ovaries. More specifically, a half-inferior ovary has nearly equal portions of ovary above, other varying degrees of inferiority can be described by other fractions
8.
Plant reproductive morphology
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Plant reproductive morphology is the study of the physical form and structure of those parts of plants directly or indirectly concerned with sexual reproduction. Among all living organisms, flowers, which are the structures of angiosperms, are the most varied physically. Plants that are not flowering plants also have complex interplays between morphological adaptation and environmental factors in their sexual reproduction, christian Konrad Sprengel studied the reproduction of flowering plants and for the first time it was understood that the pollination process involved both biotic and abiotic interactions. Charles Darwins theories of natural selection utilized this work to build his theory of evolution, Plants have complex lifecycles involving alternation of generations. One generation, the sporophyte, gives rise to the next generation asexually via spores, spores may be identical isospores or come in different sizes, but strictly speaking, spores and sporophytes are neither male nor female because they do not produce gametes. The alternate generation, the gametophyte, produces gametes, eggs and/or sperm, a gametophyte can be be monoicous, producing both eggs and sperm or dioicous, either female or male. In the bryophytes, the gametophyte is the dominant generation. In ferns and seed plants the sporophyte is the dominant generation, the obvious visible plant, whether a small herb or a large tree, is the sporophyte, and the gametophyte is very small. In seed plants, each female gametophyte, and the spore that gives rise to it, is hidden within the sporophyte and is dependent on it for nutrition. Each male gametophyte consists of from two to four cells enclosed within the protective wall of a pollen grain. The sporophyte of a plant is often described using sexual terms based on the sexuality of the gametophyte it gives rise to. For example, a sporophyte that produces spores that give rise only to male gametophytes may be described as male, even though the sporophyte itself is asexual, producing only spores. Similarly, flowers produced by the sporophyte may be described as unisexual or bisexual, the flower is the characteristic structure concerned with sexual reproduction in flowering plants. Flowers vary enormously in their construction, a complete flower, like that of Ranunculus glaberrimus shown in the figure, has a calyx of outer sepals and a corolla of inner petals. The sepals and petals form the perianth. Next inwards there are numerous stamens, which produce pollen grains, stamens may be called the male parts of a flower and collectively form the androecium. Finally in the middle there are carpels, which at maturity one or more ovules. Carpels may be called the parts of a flower and collectively form the gynoecium
9.
Fungus
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A fungus is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from the other eukaryotic life kingdoms of plants, a characteristic that places fungi in a different kingdom from plants, bacteria and some protists, is chitin in their cell walls. Similar to animals, fungi are heterotrophs, they acquire their food by absorbing dissolved molecules, growth is their means of mobility, except for spores, which may travel through the air or water. Fungi are the principal decomposers in ecological systems and this fungal group is distinct from the structurally similar myxomycetes and oomycetes. The discipline of biology devoted to the study of fungi is known as mycology, in the past, mycology was regarded as a branch of botany, although it is now known fungi are genetically more closely related to animals than to plants. Abundant worldwide, most fungi are inconspicuous because of the size of their structures. Fungi include symbionts of plants, animals, or other fungi and they may become noticeable when fruiting, either as mushrooms or as molds. Fungi perform a role in the decomposition of organic matter and have fundamental roles in nutrient cycling. Since the 1940s, fungi have been used for the production of antibiotics, Fungi are also used as biological pesticides to control weeds, plant diseases and insect pests. Many species produce bioactive compounds called mycotoxins, such as alkaloids and polyketides, the fruiting structures of a few species contain psychotropic compounds and are consumed recreationally or in traditional spiritual ceremonies. Fungi can break down manufactured materials and buildings, and become significant pathogens of humans, losses of crops due to fungal diseases or food spoilage can have a large impact on human food supplies and local economies. The fungus kingdom encompasses a diversity of taxa with varied ecologies, life cycle strategies. However, little is known of the biodiversity of Kingdom Fungi. Advances in molecular genetics have opened the way for DNA analysis to be incorporated into taxonomy, phylogenetic studies published in the last decade have helped reshape the classification within Kingdom Fungi, which is divided into one subkingdom, seven phyla, and ten subphyla. The English word fungus is directly adopted from the Latin fungus, used in the writings of Horace, a group of all the fungi present in a particular area or geographic region is known as mycobiota, e. g. the mycobiota of Ireland. Like plants, fungi grow in soil and, in the case of mushrooms, form conspicuous fruit bodies. The fungi are now considered a kingdom, distinct from both plants and animals, from which they appear to have diverged around one billion years ago. Fungi have membrane-bound cytoplasmic organelles such as mitochondria, sterol-containing membranes and they have a characteristic range of soluble carbohydrates and storage compounds, including sugar alcohols, disaccharides, and polysaccharides
10.
Algae
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Algae is an informal term for a large, diverse group of photosynthetic organisms which are not necessarily closely related, and is thus polyphyletic. Included organisms range from unicellular genera, such as Chlorella and the diatoms, to forms, such as the giant kelp. Most are aquatic and autotrophic and lack many of the cell and tissue types, such as stomata, xylem, and phloem. No definition of algae is generally accepted, one definition is that algae have chlorophyll as their primary photosynthetic pigment and lack a sterile covering of cells around their reproductive cells. Some authors exclude all prokaryotes thus do not consider cyanobacteria as algae, Algae constitute a polyphyletic group since they do not include a common ancestor, and although their plastids seem to have a single origin, from cyanobacteria, they were acquired in different ways. Green algae are examples of algae that have primary chloroplasts derived from endosymbiotic cyanobacteria, diatoms and brown algae are examples of algae with secondary chloroplasts derived from an endosymbiotic red alga. Algae exhibit a range of reproductive strategies, from simple asexual cell division to complex forms of sexual reproduction. Algae lack the various structures that characterize land plants, such as the phyllids of bryophytes, rhizoids in nonvascular plants, and the roots, leaves, and other organs found in tracheophytes. Most are phototrophic, although some are mixotrophic, deriving energy both from photosynthesis and uptake of organic carbon either by osmotrophy, myzotrophy, or phagotrophy. Some other heterotrophic organisms, such as the apicomplexans, are derived from cells whose ancestors possessed plastids. Fossilized filamentous algae from the Vindhya basin have been dated back to 1.6 to 1.7 billion years ago, the singular alga is the Latin word for seaweed and retains that meaning in English. Although some speculate that it is related to Latin algēre, be cold, a more likely source is alliga, binding, entwining. The Ancient Greek word for seaweed was φῦκος, which could mean either the seaweed or a red dye derived from it, the Latinization, fūcus, meant primarily the cosmetic rouge. It could be any color, black, red, green, accordingly, the modern study of marine and freshwater algae is called either phycology or algology, depending on whether the Greek or Latin root is used. The name Fucus appears in a number of taxa, most algae contain chloroplasts that are similar in structure to cyanobacteria. Chloroplasts contain circular DNA like that in cyanobacteria and presumably represent reduced endosymbiotic cyanobacteria, however, the exact origin of the chloroplasts is different among separate lineages of algae, reflecting their acquisition during different endosymbiotic events. The table below describes the composition of the three groups of algae. Their lineage relationships are shown in the figure in the upper right, many of these groups contain some members that are no longer photosynthetic
11.
Bryophyte
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Bryophyte is a traditional name used to refer to all embryophytes that are non-vascular plants, namely the mosses, hornworts, and liverworts, covering around 25,000 species. They are characteristically limited in size and prefer moist habitats although they can survive in drier environments, bryophytes are usually considered to be a paraphyletic group and not a natural group, although some studies have produced contrary results. Regardless of their status, the name is convenient and remains in use as a collective term. Bryophytes produce enclosed reproductive structures, but they produce neither flowers nor seeds, the term bryophyte comes from Greek βρύον, bryon tree-moss, oyster-green + φυτόν – phyton plant. Like all land plants, bryophytes have life cycles with alternation of generations, in each cycle, a haploid gametophyte, each of whose cells contains a fixed number of unpaired chromosomes, alternates with a diploid sporophyte, whose cell contain two sets of paired chromosomes. Gametophytes produce haploid sperm and eggs which fuse to form zygotes that grow into sporophytes. Sporophytes produce haploid spores by meiosis, that grow into gametophytes, bryophytes are gametophyte dominant, meaning that the more prominent, longer-lived plant is the haploid gametophyte. The diploid sporophytes appear only occasionally and remain attached to and nutritionally dependent on the gametophyte, in bryophytes, the sporophytes are always unbranched and produce a single sporangium. Liverworts, mosses and hornworts spend most of their lives as gametophytes, gametangia, archegonia and antheridia, are produced on the gametophytes, sometimes at the tips of shoots, in the axils of leaves or hidden under thalli. Some bryophytes, such as the liverwort Marchantia, create elaborate structures to bear the gametangia that are called gametangiophores, sperm are flagellated and must swim from the antheridia that produce them to archegonia which may be on a different plant. Arthropods can assist in transfer of sperm, fertilized eggs become zygotes, which develop into sporophyte embryos inside the archegonia. Mature sporophytes remain attached to the gametophyte and they consist of a stalk called a seta and a single sporangium or capsule. Inside the sporangium, haploid spores are produced by meiosis and these are dispersed, most commonly by wind, and if they land in a suitable environment can develop into a new gametophyte. Thus bryophytes disperse by a combination of swimming sperm and spores, in a similar to lycophytes, ferns. The arrangement of antheridia and archegonia on an individual plant is usually constant within a species. The main division is between species in which the antheridia and archegonia occur on the plant and those in which they occur on different plants. The term monoicous may be used where antheridia and archegonia occur on the same gametophyte, in seed plants, monoecious is used where flowers with anthers and flowers with ovules occur on the same sporophyte and dioecious where they occur on different sporophytes. These terms occasionally may be used instead of monoicous and dioicous to describe bryophyte gametophytes, monoecious and monoicous are both derived from the Greek for one house, dioecious and dioicous from the Greek for two houses
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