Pesticides are substances that are meant to control pests, including weeds. The term pesticide includes all of the following: herbicide, insecticides nematicide, piscicide, rodenticide, insect repellent, animal repellent and fungicide; the most common of these are herbicides which account for 80% of all pesticide use. Most pesticides are intended to serve as plant protection products, which in general, protect plants from weeds, fungi, or insects. In general, a pesticide is a chemical or biological agent that deters, kills, or otherwise discourages pests. Target pests can include insects, plant pathogens, molluscs, mammals, fish and microbes that destroy property, cause nuisance, or spread disease, or are disease vectors. Along with these benefits, pesticides have drawbacks, such as potential toxicity to humans and other species; the Food and Agriculture Organization has defined pesticide as: any substance or mixture of substances intended for preventing, destroying, or controlling any pest, including vectors of human or animal disease, unwanted species of plants or animals, causing harm during or otherwise interfering with the production, storage, transport, or marketing of food, agricultural commodities and wood products or animal feedstuffs, or substances that may be administered to animals for the control of insects, arachnids, or other pests in or on their bodies.
The term includes substances intended for use as a plant growth regulator, desiccant, or agent for thinning fruit or preventing the premature fall of fruit. Used as substances applied to crops either before or after harvest to protect the commodity from deterioration during storage and transport. Pesticides can be classified by target organism, chemical structure, physical state. Biopesticides include biochemical pesticides. Plant-derived pesticides, or "botanicals", have been developing quickly; these include the pyrethroids, nicotinoids, a fourth group that includes strychnine and scilliroside. Many pesticides can be grouped into chemical families. Prominent insecticide families include organochlorines and carbamates. Organochlorine hydrocarbons could be separated into dichlorodiphenylethanes, cyclodiene compounds, other related compounds, they operate by disrupting the sodium/potassium balance of the nerve fiber, forcing the nerve to transmit continuously. Their toxicities vary but they have been phased out because of their persistence and potential to bioaccumulate.
Organophosphate and carbamates replaced organochlorines. Both operate through inhibiting the enzyme acetylcholinesterase, allowing acetylcholine to transfer nerve impulses indefinitely and causing a variety of symptoms such as weakness or paralysis. Organophosphates are quite toxic to vertebrates and have in some cases been replaced by less toxic carbamates. Thiocarbamate and dithiocarbamates are subclasses of carbamates. Prominent families of herbicides include phenoxy and benzoic acid herbicides, triazines and Chloroacetanilides. Phenoxy compounds tend to selectively kill broad-leaf weeds rather than grasses; the phenoxy and benzoic acid herbicides function similar to plant growth hormones, grow cells without normal cell division, crushing the plant's nutrient transport system. Triazines interfere with photosynthesis. Many used pesticides are not included in these families, including glyphosate; the application of pest control agents is carried out by dispersing the chemical in a solvent-surfactant system to give a homogeneous preparation.
A virus lethality study performed in 1977 demonstrated that a particular pesticide did not increase the lethality of the virus, however combinations which included some surfactants and the solvent showed that pretreatment with them markedly increased the viral lethality in the test mice. Pesticides can be classified based upon their biological mechanism application method. Most pesticides work by poisoning pests. A systemic pesticide moves inside a plant following absorption by the plant. With insecticides and most fungicides, this movement is upward and outward. Increased efficiency may be a result. Systemic insecticides, which poison pollen and nectar in the flowers, may kill bees and other needed pollinators. In 2010, the development of a new class of fungicides called; these work by taking advantage of natural defense chemicals released by plants called phytoalexins, which fungi detoxify using enzymes. The paldoxins inhibit the fungi's detoxification enzymes, they are believed to be greener.
Since before 2000 BC, humans have utilized pesticides to protect their crops. The first known pesticide was elemental sulfur dusting used in ancient Sumer about 4,500 years ago in ancient Mesopotamia; the Rig Veda, about 4,000 years old, mentions the use of poisonous plants for pest control. By the 15th century, toxic chemicals such as arsenic and lead were being applied to crops to kill pests. In the 17th century, nicotine sulfate was extracted from tobacco leaves for use as an insecticide; the 19th century saw the introduction of two more natural pesticides, derived fr
Spain the Kingdom of Spain, is a country located in Europe. Its continental European territory is situated on the Iberian Peninsula, its territory includes two archipelagoes: the Canary Islands off the coast of Africa, the Balearic Islands in the Mediterranean Sea. The African enclaves of Ceuta, Peñón de Vélez de la Gomera make Spain the only European country to have a physical border with an African country. Several small islands in the Alboran Sea are part of Spanish territory; the country's mainland is bordered to the south and east by the Mediterranean Sea except for a small land boundary with Gibraltar. With an area of 505,990 km2, Spain is the largest country in Southern Europe, the second largest country in Western Europe and the European Union, the fourth largest country in the European continent. By population, Spain is the fifth in the European Union. Spain's capital and largest city is Madrid. Modern humans first arrived in the Iberian Peninsula around 35,000 years ago. Iberian cultures along with ancient Phoenician, Greek and Carthaginian settlements developed on the peninsula until it came under Roman rule around 200 BCE, after which the region was named Hispania, based on the earlier Phoenician name Spn or Spania.
At the end of the Western Roman Empire the Germanic tribal confederations migrated from Central Europe, invaded the Iberian peninsula and established independent realms in its western provinces, including the Suebi and Vandals. The Visigoths would forcibly integrate all remaining independent territories in the peninsula, including Byzantine provinces, into the Kingdom of Toledo, which more or less unified politically and all the former Roman provinces or successor kingdoms of what was documented as Hispania. In the early eighth century the Visigothic Kingdom fell to the Moors of the Umayyad Islamic Caliphate, who arrived to rule most of the peninsula in the year 726, leaving only a handful of small Christian realms in the north and lasting up to seven centuries in the Kingdom of Granada; this led to many wars during a long reconquering period across the Iberian Peninsula, which led to the creation of the Kingdom of Leon, Kingdom of Castile, Kingdom of Aragon and Kingdom of Navarre as the main Christian kingdoms to face the invasion.
Following the Moorish conquest, Europeans began a gradual process of retaking the region known as the Reconquista, which by the late 15th century culminated in the emergence of Spain as a unified country under the Catholic Monarchs. Until Aragon had been an independent kingdom, which had expanded toward the eastern Mediterranean, incorporating Sicily and Naples, had competed with Genoa and Venice. In the early modern period, Spain became the world's first global empire and the most powerful country in the world, leaving a large cultural and linguistic legacy that includes more than 570 million Hispanophones, making Spanish the world's second-most spoken native language, after Mandarin Chinese. During the Golden Age there were many advancements in the arts, with world-famous painters such as Diego Velázquez; the most famous Spanish literary work, Don Quixote, was published during the Golden Age. Spain hosts the world's third-largest number of UNESCO World Heritage Sites. Spain is a secular parliamentary democracy and a parliamentary monarchy, with King Felipe VI as head of state.
It is a major developed country and a high income country, with the world's fourteenth largest economy by nominal GDP and sixteenth largest by purchasing power parity. It is a member of the United Nations, the European Union, the Eurozone, the Council of Europe, the Organization of Ibero-American States, the Union for the Mediterranean, the North Atlantic Treaty Organization, the Organisation for Economic Co-operation and Development, Organization for Security and Co-operation in Europe, the Schengen Area, the World Trade Organization and many other international organisations. While not an official member, Spain has a "Permanent Invitation" to the G20 summits, participating in every summit, which makes Spain a de facto member of the group; the origins of the Roman name Hispania, from which the modern name España was derived, are uncertain due to inadequate evidence, although it is documented that the Phoenicians and Carthaginians referred to the region as Spania, therefore the most accepted etymology is a Semitic-Phoenician one.
Down the centuries there have been a number of accounts and hypotheses: The Renaissance scholar Antonio de Nebrija proposed that the word Hispania evolved from the Iberian word Hispalis, meaning "city of the western world". Jesús Luis Cunchillos argues that the root of the term span is the Phoenician word spy, meaning "to forge metals". Therefore, i-spn-ya would mean "the land where metals are forged", it may be a derivation of the Phoenician I-Shpania, meaning "island of rabbits", "land of rabbits" or "edge", a reference to Spain's location at the end of the Mediterranean. The word in question means "Hyrax" due to Phoenicians confusing the two animals. Hispania may derive from the poetic use of the term Hesperia, reflecting the Greek perception of Italy as a "western land" or "land of the setting sun" (Hesperia
Plants are multicellular, predominantly photosynthetic eukaryotes of the kingdom Plantae. Plants were treated as one of two kingdoms including all living things that were not animals, all algae and fungi were treated as plants. However, all current definitions of Plantae exclude the fungi and some algae, as well as the prokaryotes. By one definition, plants form the clade Viridiplantae, a group that includes the flowering plants and other gymnosperms and their allies, liverworts and the green algae, but excludes the red and brown algae. Green plants obtain most of their energy from sunlight via photosynthesis by primary chloroplasts that are derived from endosymbiosis with cyanobacteria, their chloroplasts contain b, which gives them their green color. Some plants are parasitic or mycotrophic and have lost the ability to produce normal amounts of chlorophyll or to photosynthesize. Plants are characterized by sexual reproduction and alternation of generations, although asexual reproduction is common.
There are about 320 thousand species of plants, of which the great majority, some 260–290 thousand, are seed plants. Green plants provide a substantial proportion of the world's molecular oxygen and are the basis of most of Earth's ecosystems on land. Plants that produce grain and vegetables form humankind's basic foods, have been domesticated for millennia. Plants have many cultural and other uses, as ornaments, building materials, writing material and, in great variety, they have been the source of medicines and psychoactive drugs; the scientific study of plants is known as a branch of biology. All living things were traditionally placed into one of two groups and animals; this classification may date from Aristotle, who made the distincton between plants, which do not move, animals, which are mobile to catch their food. Much when Linnaeus created the basis of the modern system of scientific classification, these two groups became the kingdoms Vegetabilia and Animalia. Since it has become clear that the plant kingdom as defined included several unrelated groups, the fungi and several groups of algae were removed to new kingdoms.
However, these organisms are still considered plants in popular contexts. The term "plant" implies the possession of the following traits multicellularity, possession of cell walls containing cellulose and the ability to carry out photosynthesis with primary chloroplasts; when the name Plantae or plant is applied to a specific group of organisms or taxon, it refers to one of four concepts. From least to most inclusive, these four groupings are: Another way of looking at the relationships between the different groups that have been called "plants" is through a cladogram, which shows their evolutionary relationships; these are not yet settled, but one accepted relationship between the three groups described above is shown below. Those which have been called "plants" are in bold; the way in which the groups of green algae are combined and named varies between authors. Algae comprise several different groups of organisms which produce food by photosynthesis and thus have traditionally been included in the plant kingdom.
The seaweeds range from large multicellular algae to single-celled organisms and are classified into three groups, the green algae, red algae and brown algae. There is good evidence that the brown algae evolved independently from the others, from non-photosynthetic ancestors that formed endosymbiotic relationships with red algae rather than from cyanobacteria, they are no longer classified as plants as defined here; the Viridiplantae, the green plants – green algae and land plants – form a clade, a group consisting of all the descendants of a common ancestor. With a few exceptions, the green plants have the following features in common, they undergo closed mitosis without centrioles, have mitochondria with flat cristae. The chloroplasts of green plants are surrounded by two membranes, suggesting they originated directly from endosymbiotic cyanobacteria. Two additional groups, the Rhodophyta and Glaucophyta have primary chloroplasts that appear to be derived directly from endosymbiotic cyanobacteria, although they differ from Viridiplantae in the pigments which are used in photosynthesis and so are different in colour.
These groups differ from green plants in that the storage polysaccharide is floridean starch and is stored in the cytoplasm rather than in the plastids. They appear to have had a common origin with Viridiplantae and the three groups form the clade Archaeplastida, whose name implies that their chloroplasts were derived from a single ancient endosymbiotic event; this is the broadest modern definition of the term'plant'. In contrast, most other algae not only have different pigments but have chloroplasts with three or four surrounding membranes, they are not close relatives of the Archaeplastida having acquired chloroplasts separately from ingested or symbiotic green and red algae. They are thus not included in the broadest modern definition of the plant kingdom, although they were in the past; the green plants or Viridiplantae were traditionally divided into the green algae (including
An essential oil is a concentrated hydrophobic liquid containing volatile chemical compounds from plants. Essential oils are known as volatile oils, ethereal oils, aetherolea, or as the oil of the plant from which they were extracted, such as oil of clove. An essential oil is "essential" in the sense that it contains the "essence of" the plant's fragrance—the characteristic fragrance of the plant from which it is derived; the term essential used here does not mean indispensable as with the terms essential amino acid or essential fatty acid which are so called since they are nutritionally required by a given living organism. In contrast to fatty oils, essential oils evaporate without leaving a stain or residue. Essential oils are extracted by distillation by using steam. Other processes include expression, solvent extraction, absolute oil extraction, resin tapping, wax embedding, cold pressing, they are used in perfumes, cosmetics and other products, for flavoring food and drink, for adding scents to incense and household cleaning products.
Essential oils are used for aromatherapy, a form of alternative medicine in which healing effects are ascribed to aromatic compounds. Aromatherapy may be useful to induce relaxation, but there is not sufficient evidence that essential oils can treat any condition. Improper use of essential oils may cause harm including allergic reactions and skin irritation, children may be susceptible to the toxic effects of improper use. Essential oils have been used in folk medicine throughout history; the earliest recorded mention of the techniques and methods used to produce essential oils is believed to be that of Ibn al-Baitar, an Al-Andalusian physician and chemist. Rather than refer to essential oils themselves, modern works discuss specific chemical compounds of which the essential oils are composed. For example: methyl salicylate rather than "oil of wintergreen". Interest in essential oils has revived in recent decades with the popularity of aromatherapy, a branch of alternative medicine that uses essential oils and other aromatic compounds.
Oils are volatilized, diluted in a carrier oil and used in massage, diffused in the air by a nebulizer, heated over a candle flame, or burned as incense. Medical applications proposed by those who sell medicinal oils range from skin treatments to remedies for cancer and are based on historical accounts of use of essential oils for these purposes. Claims for the efficacy of medical treatments, treatment of cancers in particular, are now subject to regulation in most countries. Most common essential oils such as lavender, tea tree oil and eucalyptus are distilled. Raw plant material, consisting of the flowers, wood, roots, seeds, or peel, is put into an alembic over water; as the water is heated, the steam passes through the plant material, vaporizing the volatile compounds. The vapors flow through a coil, where they condense back to liquid, collected in the receiving vessel. Most oils are distilled in a single process. One exception is ylang-ylang, purifed through a fractional distillation; the recondensed water is referred to as a hydrosol, herbal distillate, or plant water essence, which may be sold as another fragrant product.
Hydrosols include rose water, lavender water, lemon balm, clary sage, orange blossom water. The use of herbal distillates in cosmetics is increasing. Most citrus peel oils are expressed cold-pressed. Due to the large quantities of oil in citrus peel and low cost to grow and harvest the raw materials, citrus-fruit oils are cheaper than most other essential oils. Lemon or sweet orange oils are obtained as byproducts of the citrus industry. Before the discovery of distillation, all essential oils were extracted by pressing. Most flowers contain too little volatile oil to undergo expression, but their chemical components are too delicate and denatured by the high heat used in steam distillation. Instead, a solvent such as hexane or supercritical carbon dioxide is used to extract the oils. Extracts from hexane and other hydrophobic solvents are called concretes, which are a mixture of essential oil, waxes and other lipophilic plant material. Although fragrant, concretes contain large quantities of non-fragrant waxes and resins.
Another solvent, such as ethyl alcohol, is used to extract the fragrant oil from the concrete. The alcohol solution is chilled to −18 °C for more than 48 hours which causes the waxes and lipids to precipitate out; the precipitates are filtered out and the ethanol is removed from the remaining solution by evaporation, vacuum purge, or both, leaving behind the absolute. Supercritical carbon dioxide is used as a solvent in supercritical fluid extraction; this method can avoid petrochemical residues in the product and the loss of some "top notes" when steam distillation is used. It does not yield an absolute directly; the supercritical carbon dioxide will extract both the waxes and the essential oils that make up the concrete. Subsequent processing with liquid carbon dioxide, achieved in the same extractor by lowering the extraction temperature, will separate the waxes from the essential oils; this lower temperature process prevents the denaturing of compounds. When the extraction is complete, the pressure is reduced to ambient and the carbon dioxide reverts to a gas, leaving no residue.
Florasol is another solvent used to obtain essential oils. It was developed as a refrigerant to replac
France the French Republic, is a country whose territory consists of metropolitan France in Western Europe and several overseas regions and territories. The metropolitan area of France extends from the Mediterranean Sea to the English Channel and the North Sea, from the Rhine to the Atlantic Ocean, it is bordered by Belgium and Germany to the northeast and Italy to the east, Andorra and Spain to the south. The overseas territories include French Guiana in South America and several islands in the Atlantic and Indian oceans; the country's 18 integral regions span a combined area of 643,801 square kilometres and a total population of 67.3 million. France, a sovereign state, is a unitary semi-presidential republic with its capital in Paris, the country's largest city and main cultural and commercial centre. Other major urban areas include Lyon, Toulouse, Bordeaux and Nice. During the Iron Age, what is now metropolitan France was inhabited by a Celtic people. Rome annexed the area in 51 BC, holding it until the arrival of Germanic Franks in 476, who formed the Kingdom of Francia.
The Treaty of Verdun of 843 partitioned Francia into Middle Francia and West Francia. West Francia which became the Kingdom of France in 987 emerged as a major European power in the Late Middle Ages following its victory in the Hundred Years' War. During the Renaissance, French culture flourished and a global colonial empire was established, which by the 20th century would become the second largest in the world; the 16th century was dominated by religious civil wars between Protestants. France became Europe's dominant cultural and military power in the 17th century under Louis XIV. In the late 18th century, the French Revolution overthrew the absolute monarchy, established one of modern history's earliest republics, saw the drafting of the Declaration of the Rights of Man and of the Citizen, which expresses the nation's ideals to this day. In the 19th century, Napoleon established the First French Empire, his subsequent Napoleonic Wars shaped the course of continental Europe. Following the collapse of the Empire, France endured a tumultuous succession of governments culminating with the establishment of the French Third Republic in 1870.
France was a major participant in World War I, from which it emerged victorious, was one of the Allies in World War II, but came under occupation by the Axis powers in 1940. Following liberation in 1944, a Fourth Republic was established and dissolved in the course of the Algerian War; the Fifth Republic, led by Charles de Gaulle, remains today. Algeria and nearly all the other colonies became independent in the 1960s and retained close economic and military connections with France. France has long been a global centre of art and philosophy, it hosts the world's fourth-largest number of UNESCO World Heritage Sites and is the leading tourist destination, receiving around 83 million foreign visitors annually. France is a developed country with the world's sixth-largest economy by nominal GDP, tenth-largest by purchasing power parity. In terms of aggregate household wealth, it ranks fourth in the world. France performs well in international rankings of education, health care, life expectancy, human development.
France is considered a great power in global affairs, being one of the five permanent members of the United Nations Security Council with the power to veto and an official nuclear-weapon state. It is a leading member state of the European Union and the Eurozone, a member of the Group of 7, North Atlantic Treaty Organization, Organisation for Economic Co-operation and Development, the World Trade Organization, La Francophonie. Applied to the whole Frankish Empire, the name "France" comes from the Latin "Francia", or "country of the Franks". Modern France is still named today "Francia" in Italian and Spanish, "Frankreich" in German and "Frankrijk" in Dutch, all of which have more or less the same historical meaning. There are various theories as to the origin of the name Frank. Following the precedents of Edward Gibbon and Jacob Grimm, the name of the Franks has been linked with the word frank in English, it has been suggested that the meaning of "free" was adopted because, after the conquest of Gaul, only Franks were free of taxation.
Another theory is that it is derived from the Proto-Germanic word frankon, which translates as javelin or lance as the throwing axe of the Franks was known as a francisca. However, it has been determined that these weapons were named because of their use by the Franks, not the other way around; the oldest traces of human life in what is now France date from 1.8 million years ago. Over the ensuing millennia, Humans were confronted by a harsh and variable climate, marked by several glacial eras. Early hominids led a nomadic hunter-gatherer life. France has a large number of decorated caves from the upper Palaeolithic era, including one of the most famous and best preserved, Lascaux. At the end of the last glacial period, the climate became milder. After strong demographic and agricultural development between the 4th and 3rd millennia, metallurgy appeared at the end of the 3rd millennium working gold and bronze, iron. France has numerous megalithic sites from the Neolithic period, including the exceptiona
The flowering plants known as angiosperms, Angiospermae or Magnoliophyta, are the most diverse group of land plants, with 64 orders, 416 families 13,164 known genera and c. 369,000 known species. Like gymnosperms, angiosperms are seed-producing plants. However, they are distinguished from gymnosperms by characteristics including flowers, endosperm within the seeds, the production of fruits that contain the seeds. Etymologically, angiosperm means a plant; the term comes from the Greek words sperma. The ancestors of flowering plants diverged from gymnosperms in the Triassic Period, 245 to 202 million years ago, the first flowering plants are known from 160 mya, they diversified extensively during the Early Cretaceous, became widespread by 120 mya, replaced conifers as the dominant trees from 100 to 60 mya. Angiosperms differ from other seed plants in several ways, described in the table below; these distinguishing characteristics taken together have made the angiosperms the most diverse and numerous land plants and the most commercially important group to humans.
Angiosperm stems are made up of seven layers. The amount and complexity of tissue-formation in flowering plants exceeds that of gymnosperms; the vascular bundles of the stem are arranged such that the phloem form concentric rings. In the dicotyledons, the bundles in the young stem are arranged in an open ring, separating a central pith from an outer cortex. In each bundle, separating the xylem and phloem, is a layer of meristem or active formative tissue known as cambium. By the formation of a layer of cambium between the bundles, a complete ring is formed, a regular periodical increase in thickness results from the development of xylem on the inside and phloem on the outside; the soft phloem becomes crushed, but the hard wood persists and forms the bulk of the stem and branches of the woody perennial. Owing to differences in the character of the elements produced at the beginning and end of the season, the wood is marked out in transverse section into concentric rings, one for each season of growth, called annual rings.
Among the monocotyledons, the bundles are more numerous in the young stem and are scattered through the ground tissue. They once formed the stem increases in diameter only in exceptional cases; the characteristic feature of angiosperms is the flower. Flowers show remarkable variation in form and elaboration, provide the most trustworthy external characteristics for establishing relationships among angiosperm species; the function of the flower is to ensure fertilization of the ovule and development of fruit containing seeds. The floral apparatus may arise terminally from the axil of a leaf; as in violets, a flower arises singly in the axil of an ordinary foliage-leaf. More the flower-bearing portion of the plant is distinguished from the foliage-bearing or vegetative portion, forms a more or less elaborate branch-system called an inflorescence. There are two kinds of reproductive cells produced by flowers. Microspores, which will divide to become pollen grains, are the "male" cells and are borne in the stamens.
The "female" cells called megaspores, which will divide to become the egg cell, are contained in the ovule and enclosed in the carpel. The flower may consist only of these parts, as in willow, where each flower comprises only a few stamens or two carpels. Other structures are present and serve to protect the sporophylls and to form an envelope attractive to pollinators; the individual members of these surrounding structures are known as petals. The outer series is green and leaf-like, functions to protect the rest of the flower the bud; the inner series is, in general, white or brightly colored, is more delicate in structure. It functions to attract bird pollinators. Attraction is effected by color and nectar, which may be secreted in some part of the flower; the characteristics that attract pollinators account for the popularity of flowers and flowering plants among humans. While the majority of flowers are perfect or hermaphrodite, flowering plants have developed numerous morphological and physiological mechanisms to reduce or prevent self-fertilization.
Heteromorphic flowers have short carpels and long stamens, or vice versa, so animal pollinators cannot transfer pollen to the pistil. Homomorphic flowers may employ a biochemical mechanism called self-incompatibility to discriminate between self and non-self pollen grains. In other species, the male and female parts are morphologically separated, developing on different flowers; the botanical term "Angiosperm", from the Ancient Greek αγγείον, angeíon and σπέρμα, was coined in the form Angiospermae by Paul Hermann in 1690, as the name of one of his primary divisions of the plant kingdom. This included flowering plants possessing seeds enclosed in capsules, distinguished from his Gymnospermae, or flowering plants with achenial or schizo-carpic fruits, the whole fruit or each of its pieces being here regarded as a seed and naked; the term and its antonym were maintained by Carl Linnaeus with the same sense, but with restricted application, in the names of the orders of his class Didynamia. Its use with any
Morphology is a branch of biology dealing with the study of the form and structure of organisms and their specific structural features. This includes aspects of the outward appearance, i.e. external morphology, as well as the form and structure of the internal parts like bones and organs, i.e. internal morphology. This is in contrast to physiology, which deals with function. Morphology is a branch of life science dealing with the study of gross structure of an organism or taxon and its component parts; the word "morphology" is from the Ancient Greek μορφή, morphé, meaning "form", λόγος, lógos, meaning "word, research". While the concept of form in biology, opposed to function, dates back to Aristotle, the field of morphology was developed by Johann Wolfgang von Goethe and independently by the German anatomist and physiologist Karl Friedrich Burdach. Among other important theorists of morphology are Lorenz Oken, Georges Cuvier, Étienne Geoffroy Saint-Hilaire, Richard Owen, Karl Gegenbaur and Ernst Haeckel.
In 1830, Cuvier and E. G. Saint-Hilaire engaged in a famous debate, said to exemplify the two major deviations in biological thinking at the time – whether animal structure was due to function or evolution. Comparative morphology is analysis of the patterns of the locus of structures within the body plan of an organism, forms the basis of taxonomical categorization. Functional morphology is the study of the relationship between the structure and function of morphological features. Experimental morphology is the study of the effects of external factors upon the morphology of organisms under experimental conditions, such as the effect of genetic mutation. "Anatomy" is a "branch of morphology that deals with the structure of organisms". Molecular Morphology is a term used in English-speaking countries for describing the structure of compound molecules, such as polymers and ribonucleic acid. Gross Morphology refers to the collective structures of an organism as a whole as a general description of the form and structure of an organism, taking into account all of its structures without specifying an individual structure.
Most taxa differ morphologically from other taxa. Related taxa differ much less than more distantly related ones, but there are exceptions to this. Cryptic species are species which look similar, or even outwardly identical, but are reproductively isolated. Conversely, sometimes unrelated taxa acquire a similar appearance as a result of convergent evolution or mimicry. In addition, there can be morphological differences within a species, such as in Apoica flavissima where queens are smaller than workers. A further problem with relying on morphological data is that what may appear, morphologically speaking, to be two distinct species, may in fact be shown by DNA analysis to be a single species; the significance of these differences can be examined through the use of allometric engineering in which one or both species are manipulated to phenocopy the other species. A step relevant to the evaluation of morphology between traits/features within species, includes an assessment of the terms: homology and homoplasy.
Homology between features indicate. Alternatively, homoplasy between features describes those that can resemble each other, but derive independently via parallel or convergent evolution. Invention and development of microscopy enable the observation of 3-D cell morphology with both high spatial and temporal resolution; the dynamic processes of these cell morphology which are controlled by a complex system play an important role in varied important biological process, such as immune and invasive responses. Comparative anatomy Insect morphology Morphometrics Neuromorphology Phenetics Phenotype Phenotypic plasticity Plant morphology Media related to Morphology at Wikimedia Commons