In biology , a kingdom is the second highest taxonomic rank , just below domain . Kingdoms are divided into smaller groups called phyla (singular phylum).
44-396: Enantia Oliv. Annickia is a genus of plant in family Annonaceae . Every species of this genus is native to continental Africa, from west Tropical Africa to Tanzania . As accepted by Kew; A revision of the genus Annickia was carried out in 2007. This Annonaceae article is a stub . You can help Misplaced Pages by expanding it . Plant See text Plants are
88-585: A distinct nucleus ( prokaryotes ) and organisms whose cells do have a distinct nucleus ( eukaryotes ). In 1937 Édouard Chatton introduced the terms "prokaryote" and "eukaryote" to differentiate these organisms. In 1938, Herbert F. Copeland proposed a four-kingdom classification by creating the novel Kingdom Monera of prokaryotic organisms; as a revised phylum Monera of the Protista, it included organisms now classified as Bacteria and Archaea . Ernst Haeckel, in his 1904 book The Wonders of Life , had placed
132-551: A protective response. The first such plant receptors were identified in rice and in Arabidopsis thaliana . Plants have some of the largest genomes of all organisms. The largest plant genome (in terms of gene number) is that of wheat ( Triticum aestivum ), predicted to encode ≈94,000 genes and thus almost 5 times as many as the human genome . The first plant genome sequenced was that of Arabidopsis thaliana which encodes about 25,500 genes. In terms of sheer DNA sequence,
176-420: A range of physical and biotic stresses which cause DNA damage , but they can tolerate and repair much of this damage. Plants reproduce to generate offspring, whether sexually , involving gametes , or asexually , involving ordinary growth. Many plants use both mechanisms. When reproducing sexually, plants have complex lifecycles involving alternation of generations . One generation, the sporophyte , which
220-721: A third kingdom of life, the Protista , for "neutral organisms" or "the kingdom of primitive forms", which were neither animal nor plant; he did not include the Regnum Lapideum in his scheme. Haeckel revised the content of this kingdom a number of times before settling on a division based on whether organisms were unicellular (Protista) or multicellular (animals and plants). Kingdom Protista or Protoctista Kingdom Plantae Kingdom Animalia Regnum Lapideum (minerals) The development of microscopy revealed important distinctions between those organisms whose cells do not have
264-615: A third kingdom, Regnum Lapideum . Regnum Animale (animals) Regnum Vegetabile ('vegetables'/plants) Regnum Lapideum (minerals) In 1674, Antonie van Leeuwenhoek , often called the "father of microscopy", sent the Royal Society of London a copy of his first observations of microscopic single-celled organisms. Until then, the existence of such microscopic organisms was entirely unknown. Despite this, Linnaeus did not include any microscopic creatures in his original taxonomy. At first, microscopic organisms were classified within
308-489: A traditional two-kingdom system of animals and plants, dividing the plant kingdom into subkingdoms Prokaryota (bacteria and cyanobacteria), Mycota (fungi and supposed relatives), and Chlorota (algae and land plants). Kingdom Monera Kingdom Protista or Protoctista Kingdom Plantae Kingdom Fungi Kingdom Animalia Kingdom Monera Kingdom Protista Kingdom Plantae Kingdom Fungi Kingdom Animalia In 1977, Carl Woese and colleagues proposed
352-404: Is diploid (with 2 sets of chromosomes ), gives rise to the next generation, the gametophyte , which is haploid (with one set of chromosomes). Some plants also reproduce asexually via spores . In some non-flowering plants such as mosses, the sexual gametophyte forms most of the visible plant. In seed plants (gymnosperms and flowering plants), the sporophyte forms most of the visible plant, and
396-547: Is a similar process. Structures such as runners enable plants to grow to cover an area, forming a clone . Many plants grow food storage structures such as tubers or bulbs which may each develop into a new plant. Some non-flowering plants, such as many liverworts, mosses and some clubmosses, along with a few flowering plants, grow small clumps of cells called gemmae which can detach and grow. Plants use pattern-recognition receptors to recognize pathogens such as bacteria that cause plant diseases. This recognition triggers
440-742: Is an ancient one. Aristotle (384–322 BC) classified animal species in his History of Animals , while his pupil Theophrastus ( c. 371 – c. 287 BC ) wrote a parallel work, the Historia Plantarum , on plants. Carl Linnaeus (1707–1778) laid the foundations for modern biological nomenclature , now regulated by the Nomenclature Codes , in 1735. He distinguished two kingdoms of living things: Regnum Animale (' animal kingdom') and Regnum Vegetabile ('vegetable kingdom', for plants ). Linnaeus also included minerals in his classification system , placing them in
484-563: Is commonly used in recent US high school biology textbooks, but has received criticism for compromising the current scientific consensus. But the division of prokaryotes into two kingdoms remains in use with the recent seven kingdoms scheme of Thomas Cavalier-Smith, although it primarily differs in that Protista is replaced by Protozoa and Chromista . Kingdom Eubacteria (Bacteria) Kingdom Archaebacteria (Archaea) Kingdom Protista or Protoctista Kingdom Plantae Kingdom Fungi Kingdom Animalia Thomas Cavalier-Smith supported
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#1732797747116528-496: Is known as botany , a branch of biology . All living things were traditionally placed into one of two groups, plants and animals . This classification dates from Aristotle (384–322 BC), who distinguished different levels of beings in his biology , based on whether living things had a "sensitive soul" or like plants only a "vegetative soul". Theophrastus , Aristotle's student, continued his work in plant taxonomy and classification. Much later, Linnaeus (1707–1778) created
572-635: The Antarctic flora , consisting of algae, mosses, liverworts, lichens, and just two flowering plants, have adapted to the prevailing conditions on that southern continent. Plants are often the dominant physical and structural component of the habitats where they occur. Many of the Earth's biomes are named for the type of vegetation because plants are the dominant organisms in those biomes, such as grassland , savanna , and tropical rainforest . Kingdom (biology) Traditionally, textbooks from Canada and
616-706: The Cretaceous so rapid that Darwin called it an " abominable mystery ". Conifers diversified from the Late Triassic onwards, and became a dominant part of floras in the Jurassic . In 2019, a phylogeny based on genomes and transcriptomes from 1,153 plant species was proposed. The placing of algal groups is supported by phylogenies based on genomes from the Mesostigmatophyceae and Chlorokybophyceae that have since been sequenced. Both
660-457: The carpels or ovaries , which develop into fruits that contain seeds . Fruits may be dispersed whole, or they may split open and the seeds dispersed individually. Plants reproduce asexually by growing any of a wide variety of structures capable of growing into new plants. At the simplest, plants such as mosses or liverworts may be broken into pieces, each of which may regrow into whole plants. The propagation of flowering plants by cuttings
704-623: The eukaryotes that form the kingdom Plantae ; they are predominantly photosynthetic . This means that they obtain their energy from sunlight , using chloroplasts derived from endosymbiosis with cyanobacteria to produce sugars from carbon dioxide and water, using the green pigment chlorophyll . Exceptions are parasitic plants that have lost the genes for chlorophyll and photosynthesis, and obtain their energy from other plants or fungi. Most plants are multicellular , except for some green algae. Historically, as in Aristotle's biology ,
748-469: The two-empire system of prokaryotes and eukaryotes. The two-empire system would later be expanded to the three-domain system of Archaea, Bacteria, and Eukaryota. Kingdom Monera Kingdom Protista or Protoctista Kingdom Plantae Kingdom Animalia The differences between fungi and other organisms regarded as plants had long been recognised by some; Haeckel had moved the fungi out of Plantae into Protista after his original classification, but
792-1003: The "chlorophyte algae" and the "streptophyte algae" are treated as paraphyletic (vertical bars beside phylogenetic tree diagram) in this analysis, as the land plants arose from within those groups. The classification of Bryophyta is supported both by Puttick et al. 2018, and by phylogenies involving the hornwort genomes that have also since been sequenced. Rhodophyta [REDACTED] Glaucophyta [REDACTED] Chlorophyta [REDACTED] Prasinococcales Mesostigmatophyceae Chlorokybophyceae Spirotaenia [REDACTED] Klebsormidiales [REDACTED] Chara [REDACTED] Coleochaetales [REDACTED] Hornworts [REDACTED] Liverworts [REDACTED] Mosses [REDACTED] Lycophytes [REDACTED] [REDACTED] Gymnosperms [REDACTED] Angiosperms [REDACTED] Plant cells have distinctive features that other eukaryotic cells (such as those of animals) lack. These include
836-574: The United States have used a system of six kingdoms ( Animalia , Plantae , Fungi , Protista , Archaea /Archaebacteria, and Bacteria or Eubacteria), while textbooks in other parts of the world, such as Bangladesh, Brazil, Greece, India, Pakistan, Spain, and the United Kingdom have used five kingdoms (Animalia, Plantae, Fungi, Protista and Monera ). Some recent classifications based on modern cladistics have explicitly abandoned
880-864: The Viridiplantae, along with the red algae and the glaucophytes , in the clade Archaeplastida . There are about 380,000 known species of plants, of which the majority, some 260,000, produce seeds . They range in size from single cells to the tallest trees . Green plants provide a substantial proportion of the world's molecular oxygen; the sugars they create supply the energy for most of Earth's ecosystems and other organisms , including animals, either eat plants directly or rely on organisms which do so. Grain , fruit , and vegetables are basic human foods and have been domesticated for millennia. People use plants for many purposes , such as building materials , ornaments, writing materials , and, in great variety, for medicines . The scientific study of plants
924-801: The amount of cytoplasm stays the same. Most plants are multicellular . Plant cells differentiate into multiple cell types, forming tissues such as the vascular tissue with specialized xylem and phloem of leaf veins and stems , and organs with different physiological functions such as roots to absorb water and minerals, stems for support and to transport water and synthesized molecules, leaves for photosynthesis, and flowers for reproduction. Plants photosynthesize , manufacturing food molecules ( sugars ) using energy obtained from light . Plant cells contain chlorophylls inside their chloroplasts, which are green pigments that are used to capture light energy. The end-to-end chemical equation for photosynthesis is: This causes plants to release oxygen into
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#1732797747116968-521: The animal and plant kingdoms. However, by the mid–19th century, it had become clear to many that "the existing dichotomy of the plant and animal kingdoms [had become] rapidly blurred at its boundaries and outmoded". In 1860 John Hogg proposed the Protoctista , a third kingdom of life composed of "all the lower creatures, or the primary organic beings"; he retained Regnum Lapideum as a fourth kingdom of minerals. In 1866, Ernst Haeckel also proposed
1012-431: The atmosphere. Green plants provide a substantial proportion of the world's molecular oxygen, alongside the contributions from photosynthetic algae and cyanobacteria. Plants that have secondarily adopted a parasitic lifestyle may lose the genes involved in photosynthesis and the production of chlorophyll. Growth is determined by the interaction of a plant's genome with its physical and biotic environment. Factors of
1056-467: The basis of the modern system of scientific classification , but retained the animal and plant kingdoms , naming the plant kingdom the Vegetabilia. When the name Plantae or plant is applied to a specific group of organisms or taxa , it usually refers to one of four concepts. From least to most inclusive, these four groupings are: There are about 382,000 accepted species of plants, of which
1100-502: The blue-green algae (or Phycochromacea) in Monera; this would gradually gain acceptance, and the blue-green algae would become classified as bacteria in the phylum Cyanobacteria . In the 1960s, Roger Stanier and C. B. van Niel promoted and popularized Édouard Chatton's earlier work, particularly in their paper of 1962, "The Concept of a Bacterium"; this created, for the first time, a rank above kingdom—a superkingdom or empire —with
1144-436: The consensus at that time, that the difference between Eubacteria and Archaebacteria was so great (particularly considering the genetic distance of ribosomal genes) that the prokaryotes needed to be separated into two different kingdoms. He then divided Eubacteria into two subkingdoms: Negibacteria ( Gram-negative bacteria ) and Posibacteria ( Gram-positive bacteria ). Technological advances in electron microscopy allowed
1188-488: The development of forests in swampy environments dominated by clubmosses and horsetails, including some as large as trees, and the appearance of early gymnosperms , the first seed plants . The Permo-Triassic extinction event radically changed the structures of communities. This may have set the scene for the evolution of flowering plants in the Triassic (~ 200 million years ago ), with an adaptive radiation in
1232-625: The fundamental subdivision of the prokaryotes into the Eubacteria (later called the Bacteria) and Archaebacteria (later called the Archaea), based on ribosomal RNA structure; this would later lead to the proposal of three "domains" of life , of Bacteria, Archaea, and Eukaryota. Combined with the five-kingdom model, this created a six-kingdom model, where the kingdom Monera is replaced by the kingdoms Bacteria and Archaea. This six-kingdom model
1276-409: The gametophyte is very small. Flowering plants reproduce sexually using flowers, which contain male and female parts: these may be within the same ( hermaphrodite ) flower, on different flowers on the same plant , or on different plants . The stamens create pollen , which produces male gametes that enter the ovule to fertilize the egg cell of the female gametophyte. Fertilization takes place within
1320-583: The great majority, some 283,000, produce seeds . The table below shows some species count estimates of different green plant (Viridiplantae) divisions . About 85–90% of all plants are flowering plants. Several projects are currently attempting to collect records on all plant species in online databases, e.g. the World Flora Online . Plants range in scale from single-celled organisms such as desmids (from 10 micrometres (μm) across) and picozoa (less than 3 μm across), to
1364-460: The highest rank was given the name "kingdom" and was followed by four other main or principal ranks: class , order , genus and species . Later two further main ranks were introduced, making the sequence kingdom, phylum or division , class , order , family , genus and species . In 1990, the rank of domain was introduced above kingdom. Prefixes can be added so subkingdom ( subregnum ) and infrakingdom (also known as infraregnum ) are
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1408-529: The land 1,200 million years ago , but it was not until the Ordovician , around 450 million years ago , that the first land plants appeared, with a level of organisation like that of bryophytes. However, fossils of organisms with a flattened thallus in Precambrian rocks suggest that multicellular freshwater eukaryotes existed over 1000 mya. Primitive land plants began to diversify in
1452-412: The large water-filled central vacuole , chloroplasts , and the strong flexible cell wall , which is outside the cell membrane . Chloroplasts are derived from what was once a symbiosis of a non-photosynthetic cell and photosynthetic cyanobacteria . The cell wall, made mostly of cellulose , allows plant cells to swell up with water without bursting. The vacuole allows the cell to change in size while
1496-515: The largest trees ( megaflora ) such as the conifer Sequoia sempervirens (up to 120 metres (380 ft) tall) and the angiosperm Eucalyptus regnans (up to 100 m (325 ft) tall). The naming of plants is governed by the International Code of Nomenclature for algae, fungi, and plants and the International Code of Nomenclature for Cultivated Plants . The ancestors of land plants evolved in water. An algal scum formed on
1540-665: The late Silurian , around 420 million years ago . Bryophytes, club mosses, and ferns then appear in the fossil record. Early plant anatomy is preserved in cellular detail in an early Devonian fossil assemblage from the Rhynie chert . These early plants were preserved by being petrified in chert formed in silica-rich volcanic hot springs. By the end of the Devonian, most of the basic features of plants today were present, including roots, leaves and secondary wood in trees such as Archaeopteris . The Carboniferous period saw
1584-501: The physical or abiotic environment include temperature , water , light, carbon dioxide , and nutrients in the soil. Biotic factors that affect plant growth include crowding, grazing, beneficial symbiotic bacteria and fungi, and attacks by insects or plant diseases . Frost and dehydration can damage or kill plants. Some plants have antifreeze proteins , heat-shock proteins and sugars in their cytoplasm that enable them to tolerate these stresses . Plants are continuously exposed to
1628-538: The plant kingdom encompassed all living things that were not animals , and included algae and fungi . Definitions have narrowed since then; current definitions exclude the fungi and some of the algae. By the definition used in this article, plants form the clade Viridiplantae (green plants), which consists of the green algae and the embryophytes or land plants ( hornworts , liverworts , mosses , lycophytes , ferns , conifers and other gymnosperms , and flowering plants ). A definition based on genomes includes
1672-480: The result of the endosymbiosis of a proteobacterium , it was thought that these amitochondriate eukaryotes were primitively so, marking an important step in eukaryogenesis . As a result, these amitochondriate protists were separated from the protist kingdom, giving rise to the, at the same time, superkingdom and kingdom Archezoa . This superkingdom was opposed to the Metakaryota superkingdom, grouping together
1716-595: The separation of the Chromista from the Plantae kingdom. Indeed, the chloroplast of the chromists is located in the lumen of the endoplasmic reticulum instead of in the cytosol . Moreover, only chromists contain chlorophyll c . Since then, many non-photosynthetic phyla of protists, thought to have secondarily lost their chloroplasts, were integrated into the kingdom Chromista. Finally, some protists lacking mitochondria were discovered. As mitochondria were known to be
1760-469: The smallest published genome is that of the carnivorous bladderwort ( Utricularia gibba) at 82 Mb (although it still encodes 28,500 genes) while the largest, from the Norway spruce ( Picea abies ), extends over 19.6 Gb (encoding about 28,300 genes). Plants are distributed almost worldwide. While they inhabit several biomes which can be divided into a multitude of ecoregions , only the hardy plants of
1804-431: The term kingdom , noting that some traditional kingdoms are not monophyletic , meaning that they do not consist of all the descendants of a common ancestor . The terms flora (for plants), fauna (for animals), and, in the 21st century, funga (for fungi) are also used for life present in a particular region or time. When Carl Linnaeus introduced the rank-based system of nomenclature into biology in 1735,
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1848-561: The two empire system. In the Whittaker system, Plantae included some algae. In other systems, such as Lynn Margulis 's system of five kingdoms, the plants included just the land plants ( Embryophyta ), and Protoctista has a broader definition. Following publication of Whittaker's system, the five-kingdom model began to be commonly used in high school biology textbooks. But despite the development from two kingdoms to five among most scientists, some authors as late as 1975 continued to employ
1892-450: The two ranks immediately below kingdom. Superkingdom may be considered as an equivalent of domain or empire or as an independent rank between kingdom and domain or subdomain. In some classification systems the additional rank branch (Latin: ramus ) can be inserted between subkingdom and infrakingdom, e.g., Protostomia and Deuterostomia in the classification of Cavalier-Smith. The classification of living things into animals and plants
1936-724: Was largely ignored in this separation by scientists of his time. Robert Whittaker recognized an additional kingdom for the Fungi . The resulting five-kingdom system, proposed in 1969 by Whittaker, has become a popular standard and with some refinement is still used in many works and forms the basis for new multi-kingdom systems. It is based mainly upon differences in nutrition ; his Plantae were mostly multicellular autotrophs , his Animalia multicellular heterotrophs , and his Fungi multicellular saprotrophs . The remaining two kingdoms, Protista and Monera, included unicellular and simple cellular colonies. The five kingdom system may be combined with
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