Hydroponics is a subset of hydroculture, a method of growing plants without soil by using mineral nutrient solutions in a water solvent. Terrestrial plants may be grown with only their roots exposed to the mineral solution, or the roots may be supported by an inert medium, such as perlite or gravel; the nutrients used in hydroponic systems can come from an array of different sources. The earliest published work on growing terrestrial plants without soil was the 1627 book Sylva Sylvarum or'A Natural History' by Francis Bacon, printed a year after his death. Water culture became a popular research technique after that. In 1699, John Woodward published his water culture experiments with spearmint, he found. By 1842, a list of nine elements believed to be essential for plant growth had been compiled, the discoveries of German botanists Julius von Sachs and Wilhelm Knop, in the years 1859–1875, resulted in a development of the technique of soilless cultivation. Growth of terrestrial plants without soil in mineral nutrient solutions was called solution culture.
It became a standard research and teaching technique and is still used. Solution culture is, a type of hydroponics where there is no inert medium. In 1929, William Frederick Gericke of the University of California at Berkeley began publicly promoting that solution culture be used for agricultural crop production, he first termed it aquaculture but found that aquaculture was applied to culture of aquatic organisms. Gericke created a sensation by growing tomato vines twenty-five feet high in his back yard in mineral nutrient solutions rather than soil, he introduced the term hydroponics, water culture, in 1937, proposed to him by W. A. Setchell, a phycologist with an extensive education in the classics. Hydroponics is derived from neologism υδρωπονικά, constructed in analogy to γεωπονικά, that which concerns agriculture, replacing, γεω-, with ὑδρο-, water. Reports of Gericke's work and his claims that hydroponics would revolutionize plant agriculture prompted a huge number of requests for further information.
Gericke had been denied use of the University's greenhouses for his experiments due to the administration's skepticism, when the University tried to compel him to release his preliminary nutrient recipes developed at home he requested greenhouse space and time to improve them using appropriate research facilities. While he was provided greenhouse space, the University assigned Hoagland and Arnon to re-develop Gericke's formula and show it held no benefit over soil grown plant yields, a view held by Hoagland. In 1940, Gericke published the book, Complete Guide to Soil less Gardening, after leaving his academic position in a climate, politically unfavorable. Two other plant nutritionists, Dennis R. Hoagland and Daniel I. Arnon, at the University of California were asked to research Gericke's claims; the two wrote a classic 1938 agricultural bulletin, The Water Culture Method for Growing Plants Without Soil, which made the claim that hydroponic crop yields were no better than crop yields with good-quality soils.
Crop yields were limited by factors other than mineral nutrients light. This research, overlooked the fact that hydroponics has other advantages including the fact that the roots of the plant have constant access to oxygen and that the plants have access to as much or as little water as they need; this is important as one of the most common errors. In soil, a grower needs to be experienced to know how much water to feed the plant. Too much and the plant will be unable to access oxygen; these two researchers developed several formulas for mineral nutrient solutions, known as Hoagland solution. Modified Hoagland solutions are still in use. One of the earliest successes of hydroponics occurred on Wake Island, a rocky atoll in the Pacific Ocean used as a refueling stop for Pan American Airlines. Hydroponics was used there in the 1930s to grow vegetables for the passengers. Hydroponics was a necessity on Wake Island because there was no soil, it was prohibitively expensive to airlift in fresh vegetables.
In the 1960s, Allen Cooper of England developed the Nutrient film technique. The Land Pavilion at Walt Disney World's EPCOT Center opened in 1982 and prominently features a variety of hydroponic techniques. In recent decades, NASA has done extensive hydroponic research for its Controlled Ecological Life Support System. Hydroponics research mimicking a Martian environment uses LED lighting to grow in a different color spectrum with much less heat. Ray Wheeler, a plant physiologist at Kennedy Space Center’s Space Life Science Lab, believes that hydroponics will create advances within space travel, as a bioregenerative life support system. In 2007, Eurofresh Farms in Willcox, sold more than 200 million pounds of hydroponically grown tomatoes. Eurofresh has 318 acres under glass and represents about a third of the commercial hydroponic greenhouse area in the U. S. Eurofresh tomatoes were pesticide-free. Eurofres
Cottonseed oil is a cooking oil extracted from the seeds of cotton plants of various species Gossypium hirsutum and Gossypium herbaceum, that are grown for cotton fiber, animal feed, oil. Cotton seed has a similar structure to other oilseeds such as sunflower seed, having an oil-bearing kernel surrounded by a hard outer hull. Cottonseed oil is used for salad oil, salad dressing, similar products because of its flavor stability, its fatty acid profile consists of 70% unsaturated fatty acids, 26% saturated fatty acids. When it is hydrogenated, its profile is 94% saturated fat and 2% unsaturated fatty acids. According to the cottonseed oil industry, cottonseed oil does not need to be hydrogenated as much as other polyunsaturated oils to achieve similar results. Gossypol is a toxic, polyphenolic compound produced by cotton and other members of the order Malvaceae, such as okra; this occurring coloured compound is found in tiny glands in the seed, stem, tap root bark, root of the cotton plant. The adaptive function of the compound facilitates natural insect resistance.
The three key steps of refining and deodorization in producing finished oil act to eliminate the gossypol level. Ferric chloride is used to decolorize cotton seed oil. Once processed, cottonseed oil has a mild taste and appears clear with a light golden color, the amount of color depending on the amount of refining, it has a high smoke point as a frying medium. Density ranges from 0.917 g/cm3 to 0.933 g/cm3. Like other long-chain fatty acid oils, cottonseed oil has a smoke point of about 450 °F, is high in tocopherols, which contribute its stability, giving products that contain it a long shelf life, hence manufacturers' proclivity to use it in packaged goods; the by-product of cotton processing, cottonseed was considered worthless before the late 19th century. While cotton production expanded throughout the 17th, 18th, mid 19th centuries, a worthless stock of cottonseed grew. Although some of the seed was used for planting and animal feed, the majority was left to rot or was illegally dumped into rivers.
In the 1820s and 1830s Europe experienced fats and oils shortages due to rapid population expansion during the Industrial Revolution and the after-effects of the British blockade during the Napoleonic Wars. The increased demand for fats and oils, coupled with a decreasing supply caused prices to rise sharply. Many Europeans could not afford to buy the fats and oils they had used for cooking and for lighting. Many United States entrepreneurs tried to take advantage of the increasing European demand for oils and America’s large supply of cottonseed by crushing the seed for oil, but separating the seed hull from the seed meat proved difficult and most of these ventures failed within a few years. This problem was resolved in 1857, when William Fee invented a huller, which separated the tough hulls from the meats of cottonseed. With this new invention, cottonseed oil began to be used for illumination purposes in lamps to supplement expensive whale oil and lard, but by 1859, this use came to end. Cottonseed oil began to be used illegally to fortify animal fats and lards.
Meat packers secretly added cottonseed oil to the pure fats, but this practice was uncovered in 1884. Armour and Company, an American meatpacking and food processing company, sought to corner the lard market and realized that it had purchased more lard than the existing hog population could have produced. A congressional investigation followed, legislation was passed that required products fortified with cottonseed oil to be labeled as ‘‘lard compound.” Cottonseed oil was blended with olive oil. Once the practice was exposed, many countries put import tariffs on American olive oil and Italy banned the product in 1883. Both of these regulatory schemes depressed cottonseed oil sales and exports, once again creating an oversupply of cottonseed oil, which decreased its value, it was cottonseed's depressed value that led a newly formed Gamble to utilize its oil. The Panic of 1837 caused the two brothers-in-law to merge their candlestick and soap manufacturing businesses in an effort to minimize costs and weather the bear market.
Looking for a replacement for expensive animal fats in production, the brothers settled on cottonseed oil. Procter & Gamble cornered the cottonseed oil market to circumvent the meat packer's monopoly on the price, but as electricity emerged, the demand for candles decreased. Procter and Gamble found an edible use for cottonseed oil. Through patented technology, the brothers were able to hydrogenate cottonseed oil and develop a substance that resembled lard. In 1911, Procter & Gamble launched an aggressive marketing campaign to publicize its new product, Crisco, a vegetable shortening that could be used in place of lard. Crisco placed ads in major newspapers advertising that the product was "easier on digestion...a healthier alternative to cooking with animal fats... and more economical than butter.” The company gave away free cookbooks, with every recipe calling for Crisco. By the 1920s the company developed cookbooks for specific ethnicities in their native tongues. Additionally, Crisco starting airing radio cooking programs.
In 1899 David Wesson, a food chemist, developed deodorized cottonseed oil, Wesson cooking oil. Wesson Oil was marketed and became quite popular too. Over the next 30 years cottonseed oil became the pre-eminent oil in the United S
A cotyledon is a significant part of the embryo within the seed of a plant, is defined as "the embryonic leaf in seed-bearing plants, one or more of which are the first leaves to appear from a germinating seed." The number of cotyledons present is one characteristic used by botanists to classify the flowering plants. Species with one cotyledon are called monocotyledonous. Plants with two embryonic leaves are termed dicotyledonous. In the case of dicot seedlings whose cotyledons are photosynthetic, the cotyledons are functionally similar to leaves. However, true leaves and cotyledons are developmentally distinct. Cotyledons are formed during embryogenesis, along with the root and shoot meristems, are therefore present in the seed prior to germination. True leaves, are formed post-embryonically from the shoot apical meristem, responsible for generating subsequent aerial portions of the plant; the cotyledon of grasses and many other monocotyledons is a modified leaf composed of a scutellum and a coleoptile.
The scutellum is a tissue within the seed, specialized to absorb stored food from the adjacent endosperm. The coleoptile is a protective cap. Gymnosperm seedlings have cotyledons, these are variable in number, with from 2 to 24 cotyledons forming a whorl at the top of the hypocotyl surrounding the plumule. Within each species, there is still some variation in cotyledon numbers, e.g. Monterey pine seedlings have 5–9, Jeffrey pine 7–13, but other species are more fixed, with e.g. Mediterranean cypress always having just two cotyledons; the highest number reported is for big-cone pinyon, with 24. The cotyledons may be ephemeral, lasting only days after emergence, or persistent, enduring at least a year on the plant; the cotyledons contain the stored food reserves of the seed. As these reserves are used up, the cotyledons may turn green and begin photosynthesis, or may wither as the first true leaves take over food production for the seedling. Cotyledons may be either epigeal, expanding on the germination of the seed, throwing off the seed shell, rising above the ground, becoming photosynthetic.
The latter is the case where the cotyledons act as a storage organ, as in many nuts and acorns. Hypogeal plants have larger seeds than epigeal ones, they are capable of surviving if the seedling is clipped off, as meristem buds remain underground. The tradeoff is whether the plant should produce a large number of small seeds, or a smaller number of seeds which are more to survive. Related plants show a mixture of hypogeal and epigeal development within the same plant family. Groups which contain both hypogeal and epigeal species include, for example, the Araucariaceae family of Southern Hemisphere conifers, the Fabaceae, the genus Lilium; the garden grown common bean - Phaseolus vulgaris - is epigeal while the related runner bean - Phaseolus coccineus - is hypogeal. The term cotyledon was coined by Marcello Malpighi. John Ray was the first botanist to recognize that some plants have two and others only one, the first to recognize the immense importance of this fact to systematics, in Methodus plantarum.
Theophrastus and Albertus Magnus may have recognized the distinction between the dicotyledons and monocotyledons. Tiscali.reference - Cotyledon
In botany, a fruit is the seed-bearing structure in flowering plants formed from the ovary after flowering. Fruits are the means. Edible fruits, in particular, have propagated with the movements of humans and animals in a symbiotic relationship as a means for seed dispersal and nutrition. Accordingly, fruits account for a substantial fraction of the world's agricultural output, some have acquired extensive cultural and symbolic meanings. In common language usage, "fruit" means the fleshy seed-associated structures of a plant that are sweet or sour, edible in the raw state, such as apples, grapes, lemons and strawberries. On the other hand, in botanical usage, "fruit" includes many structures that are not called "fruits", such as bean pods, corn kernels and wheat grains; the section of a fungus that produces spores is called a fruiting body. Many common terms for seeds and fruit do not correspond to the botanical classifications. In culinary terminology, a fruit is any sweet-tasting plant part a botanical fruit.
However, in botany, a fruit is the ripened ovary or carpel that contains seeds, a nut is a type of fruit and not a seed, a seed is a ripened ovule. Examples of culinary "vegetables" and nuts that are botanically fruit include corn, eggplant, sweet pepper, tomato. In addition, some spices, such as allspice and chili pepper, are fruits. In contrast, rhubarb is referred to as a fruit, because it is used to make sweet desserts such as pies, though only the petiole of the rhubarb plant is edible, edible gymnosperm seeds are given fruit names, e.g. ginkgo nuts and pine nuts. Botanically, a cereal grain, such as corn, rice, or wheat, is a kind of fruit, termed a caryopsis. However, the fruit wall is thin and is fused to the seed coat, so all of the edible grain is a seed; the outer edible layer, is the pericarp, formed from the ovary and surrounding the seeds, although in some species other tissues contribute to or form the edible portion. The pericarp may be described in three layers from outer to inner, the epicarp and endocarp.
Fruit that bears a prominent pointed terminal projection is said to be beaked. A fruit results from maturation of one or more flowers, the gynoecium of the flower forms all or part of the fruit. Inside the ovary/ovaries are one or more ovules where the megagametophyte contains the egg cell. After double fertilization, these ovules will become seeds; the ovules are fertilized in a process that starts with pollination, which involves the movement of pollen from the stamens to the stigma of flowers. After pollination, a tube grows from the pollen through the stigma into the ovary to the ovule and two sperm are transferred from the pollen to the megagametophyte. Within the megagametophyte one of the two sperm unites with the egg, forming a zygote, the second sperm enters the central cell forming the endosperm mother cell, which completes the double fertilization process; the zygote will give rise to the embryo of the seed, the endosperm mother cell will give rise to endosperm, a nutritive tissue used by the embryo.
As the ovules develop into seeds, the ovary begins to ripen and the ovary wall, the pericarp, may become fleshy, or form a hard outer covering. In some multiseeded fruits, the extent to which the flesh develops is proportional to the number of fertilized ovules; the pericarp is differentiated into two or three distinct layers called the exocarp and endocarp. In some fruits simple fruits derived from an inferior ovary, other parts of the flower, fuse with the ovary and ripen with it. In other cases, the sepals, petals and/or stamens and style of the flower fall off; when such other floral parts are a significant part of the fruit, it is called an accessory fruit. Since other parts of the flower may contribute to the structure of the fruit, it is important to study flower structure to understand how a particular fruit forms. There are three general modes of fruit development: Apocarpous fruits develop from a single flower having one or more separate carpels, they are the simplest fruits. Syncarpous fruits develop from a single gynoecium having two or more carpels fused together.
Multiple fruits form from many different flowers. Plant scientists have grouped fruits into three main groups, simple fruits, aggregate fruits, composite or multiple fruits; the groupings are not evolutionarily relevant, since many diverse plant taxa may be in the same group, but reflect how the flower organs are arranged and how the fruits develop. Simple fruits can be either dry or fleshy, result from the ripening of a simple or compound ovary in a flower with only one pistil. Dry fruits may be either dehiscent, or indehiscent. Types of dry, simple fruits, examples of each, include: achene – most seen in aggregate fruits capsule – caryopsis – cypsela – an achene-like fruit derived from the individual florets in a capitulum. Fibrous drupe – follicle – is formed from a single carpel, opens by one suture
Potash is some of various mined and manufactured salts that contain potassium in water-soluble form. The name derives from pot ash, which refers to plant ashes soaked in water in a pot, the primary means of manufacturing the product before the industrial era; the word potassium is derived from potash. Potash is produced worldwide at amounts exceeding 90 million tonnes per year for use in manufacturing. Various types of fertilizer-potash constitute the single largest industrial use of the element potassium in the world. Potassium was first derived in 1807 by electrolysis of caustic potash. Potash refers to potassium compounds and potassium-bearing materials, the most common being potassium chloride; the term potash comes from the Middle Dutch word potaschen. The old method of making potassium carbonate was by collecting or producing wood ash, leaching the ashes and evaporating the resulting solution in large iron pots, leaving a white residue called pot ash. 10% by weight of common wood ash can be recovered as pot ash.
Potash became the term applied to occurring potassium salts and the commercial product derived from them. The following table lists a number of potassium compounds which use the word potash in their traditional names: All commercial potash deposits come from evaporite deposits and are buried deep below the earth's surface. Potash ores are rich in potassium chloride, sodium chloride and other salts and clays, are obtained by conventional shaft mining with the extracted ore ground into a powder. Other methods include dissolution evaporation methods from brines. In the evaporation method, hot water is injected into the potash, dissolved and pumped to the surface where it is concentrated by solar induced evaporation. Amine reagents are added to either the mined or evaporated solutions; the amine coats the KCl but not NaCl. Air bubbles cling to the amine + KCl and float it to the surface while the NaCl and clay sink to the bottom; the surface is skimmed for the amine + KCl, dried and packaged for use as a K rich fertilizer—KCl dissolves in water and is available for plant nutrition.
Potash deposits can be found all over the world. At present, deposits are being mined in Canada, China, Israel, Chile, the United States, Spain, the United Kingdom and Brazil, with the most significant deposits present in Saskatchewan, Canada. Excessive respiratory disease has been a concern for potash miners throughout history due to environmental hazards, such as radon and asbestos. Potash miners are liable to develop silicosis. Based on a study done between 1977 and 1987 cardiovascular disease among potash workers, the overall mortality rates were low, but a noticeable difference in above ground workers was documented. Potash has been used in bleaching textiles, making glass, making soap, since about AD 500. Potash was principally obtained by leaching the ashes of sea plants. Beginning in the 14th century potash was mined in Ethiopia. One of the world's largest deposits, 140 to 150 million tons, is located in the Tigray's Dallol area. Potash was one of the most important industrial chemicals.
It was refined from the ashes of broadleaved trees and produced in the forested areas of Europe and North America. The first U. S. patent of any kind was issued in 1790 to Samuel Hopkins for an improvement "in the making of Pot ash and Pearl ash by a new Apparatus and Process". Pearl ash was a purer quality made by calcination of potash in kiln. Potash pits were once used in England to produce potash, used in making soap for the preparation of wool for yarn production; as early as 1767, potash from wood ashes was exported from Canada, exports of potash and pearl ash reached 43,958 barrels in 1865. There were 519 asheries in operation in 1871; the industry declined in the late 19th century when large-scale production of potash from mineral salts was established in Germany. In 1943, potash was discovered in Canada, in the process of drilling for oil. Active exploration began in 1951. In 1958, the Potash Company of America became the first potash producer in Canada with the commissioning of an underground potash mine at Patience Lake.
The underground mine was flooded in 1987 and was reactivated for commercial production as a solution mine in 1989. In the late 18th and early 19th centuries, potash production provided settlers in North America a way to obtain badly needed cash and credit as they cleared wooded land for crops. To make full use of their land, settlers needed to dispose of excess wood; the easiest way to accomplish this was to burn any wood not needed for construction. Ashes from hardwood trees could be used to make lye, which could either be used to make soap or boiled down to produce valuable potash. Hardwood could generate ashes at the rate of 60 to 100 bushels per acre. In 1790, ashes could be sold for $3.25 to $6.25 per acre in rural New York State – nearly the same rate as hiring a laborer to clear the same area. Potash making became a major industry in British North America. Great Britain was always the most important market; the American potash industry followed the woodsman's ax across the country. After about 1820, New York replaced New England as the most important source.
Potash production was always
Liquid–liquid extraction known as solvent extraction and partitioning, is a method to separate compounds or metal complexes, based on their relative solubilities in two different immiscible liquids water and an organic solvent. There is a net transfer of one or more species from one liquid into another liquid phase from aqueous to organic; the transfer is driven by chemical potential, i.e. once the transfer is complete, the overall system of protons and electrons that make up the solutes and the solvents are in a more stable configuration. The solvent, enriched in solute is called extract; the feed solution, depleted in solute is called the raffinate. LLE is a basic technique in chemical laboratories, where it is performed using a variety of apparatus, from separatory funnels to countercurrent distribution equipment called as mixer settlers; this type of process is performed after a chemical reaction as part of the work-up including an acidic work-up. The term partitioning is used to refer to the underlying chemical and physical processes involved in liquid–liquid extraction, but on another reading may be synonymous with it.
The term solvent extraction can refer to the separation of a substance from a mixture by preferentially dissolving that substance in a suitable solvent. In that case, a soluble compound is separated from a complex matrix. From a hydrometallurgical perspective, solvent extraction is used in separation and purification of uranium and plutonium and hafnium, separation of cobalt and nickel and purification of rare earth elements etc. its greatest advantage being its ability to selectively separate out very similar metals. One obtains high-purity single metal streams on'stripping' out the metal value from the'loaded' organic wherein one can precipitate or deposit the metal value. Stripping is the opposite of extraction: Transfer of mass from organic to aqueous phase. LLE is widely used in the production of fine organic compounds, the processing of perfumes, the production of vegetable oils and biodiesel, other industries, it is among the most common initial separation techniques, though some difficulties result in extracting out related functional groups.
Liquid–liquid extraction is possible in non-aqueous systems: In a system consisting of a molten metal in contact with molten salts, metals can be extracted from one phase to the other. This is related to a mercury electrode where a metal can be reduced, the metal will then dissolve in the mercury to form an amalgam that modifies its electrochemistry greatly. For example, it is possible for sodium cations to be reduced at a mercury cathode to form sodium amalgam, while at an inert electrode the sodium cations are not reduced. Instead, water is reduced to hydrogen. A detergent or fine solid can be used to stabilize third phase. In solvent extraction, a distribution ratio is quoted as a measure of how well-extracted a species is; the distribution ratio is equal to the concentration of a solute in the organic phase divided by its concentration in the aqueous phase. Depending on the system, the distribution ratio can be a function of temperature, the concentration of chemical species in the system, a large number of other parameters.
Note that D is related to the ΔG of the extraction process. Sometimes, the distribution ratio is referred to as the partition coefficient, expressed as the logarithm. Note that a distribution ratio for uranium and neptunium between two inorganic solids has been reported. In solvent extraction, two immiscible liquids are shaken together; the more polar solutes dissolve preferentially in the more polar solvent, the less polar solutes in the less polar solvent. In this experiment, the nonpolar halogens preferentially dissolve in the non-polar mineral oil. Although the distribution ratio and partition coefficient are used synonymously, they are not so. Solutes may exist in more than one form in any particular phase, which would mean that the partition coefficient and distribution ratio will have different values; this is an important distinction to make as whilst the partition coefficient has a fixed value for the partitioning of a solute between two phases, the distribution ratio changes with differing conditions in the solvent.
After performing liquid–liquid extraction, a quantitative measure must be taken to determine the ratio of the solution’s total concentration in each phase of the extraction. This quantitative measure is known as the distribution distribution coefficient; the separation factor is one distribution ratio divided by another. For instance, if the distribution ratio for nickel is 10 and the distribution ratio for silver is 100 the silver/nickel separation factor is equal to DAg/DNi = SFAg/Ni = 10; this is used to express the ability of a process to remove a contaminant from a product. For instance, if a process is fed with a mixture of 1:9 cadmium to indium, the product is a 1:99 mixture of cadmium and indium the decontamination factor of the process is 0.11 / 0.01 = 11. The easy way to work out the extraction mechanism is to measure the slopes. If for an extraction system the D value is proportional to the square of the concentration of a reagent the slope of the graph of log10 against log10 will be two.
Success of liquid–liquid extraction is measured through separation factors and decontamination factors. The best way to understand the success of an extraction co
Genetic engineering called genetic modification or genetic manipulation, is the direct manipulation of an organism's genes using biotechnology. It is a set of technologies used to change the genetic makeup of cells, including the transfer of genes within and across species boundaries to produce improved or novel organisms. New DNA is obtained by either isolating and copying the genetic material of interest using recombinant DNA methods or by artificially synthesising the DNA. A construct is created and used to insert this DNA into the host organism; the first recombinant DNA molecule was made by Paul Berg in 1972 by combining DNA from the monkey virus SV40 with the lambda virus. As well as inserting genes, the process can be used to remove, or "knock out", genes; the new DNA can be targeted to a specific part of the genome. An organism, generated through genetic engineering is considered to be genetically modified and the resulting entity is a genetically modified organism; the first GMO was a bacterium generated by Herbert Boyer and Stanley Cohen in 1973.
Rudolf Jaenisch created the first GM animal when he inserted foreign DNA into a mouse in 1974. The first company to focus on genetic engineering, was founded in 1976 and started the production of human proteins. Genetically engineered human insulin was produced in 1978 and insulin-producing bacteria were commercialised in 1982. Genetically modified food has been sold with the release of the Flavr Savr tomato; the Flavr Savr was engineered to have a longer shelf life, but most current GM crops are modified to increase resistance to insects and herbicides. GloFish, the first GMO designed as a pet, was sold in the United States in December 2003. In 2016 salmon modified with a growth hormone were sold. Genetic engineering has been applied in numerous fields including research, industrial biotechnology and agriculture. In research GMOs are used to study gene function and expression through loss of function, gain of function and expression experiments. By knocking out genes responsible for certain conditions it is possible to create animal model organisms of human diseases.
As well as producing hormones and other drugs genetic engineering has the potential to cure genetic diseases through gene therapy. The same techniques that are used to produce drugs can have industrial applications such as producing enzymes for laundry detergent and other products; the rise of commercialised genetically modified crops has provided economic benefit to farmers in many different countries, but has been the source of most of the controversy surrounding the technology. This has been present since its early use. Although there is a scientific consensus that available food derived from GM crops poses no greater risk to human health than conventional food, GM food safety is a leading concern with critics. Gene flow, impact on non-target organisms, control of the food supply and intellectual property rights have been raised as potential issues; these concerns have led to the development of a regulatory framework, which started in 1975. It has led to an international treaty, the Cartagena Protocol on Biosafety, adopted in 2000.
Individual countries have developed their own regulatory systems regarding GMOs, with the most marked differences occurring between the US and Europe. Genetic engineering is a process that alters the genetic structure of an organism by either removing or introducing DNA. Unlike traditional animal and plant breeding, which involves doing multiple crosses and selecting for the organism with the desired phenotype, genetic engineering takes the gene directly from one organism and inserts it in the other; this is much faster, can be used to insert any genes from any organism and prevents other undesirable genes from being added. Genetic engineering could fix severe genetic disorders in humans by replacing the defective gene with a functioning one, it is an important tool in research. Drugs and other products have been harvested from organisms engineered to produce them. Crops have been developed that aid food security by increasing yield, nutritional value and tolerance to environmental stresses; the DNA can be introduced directly into the host organism or into a cell, fused or hybridised with the host.
This relies on recombinant nucleic acid techniques to form new combinations of heritable genetic material followed by the incorporation of that material either indirectly through a vector system or directly through micro-injection, macro-injection or micro-encapsulation. Genetic engineering does not include traditional breeding, in vitro fertilisation, induction of polyploidy and cell fusion techniques that do not use recombinant nucleic acids or a genetically modified organism in the process. However, some broad definitions of genetic engineering include selective breeding. Cloning and stem cell research, although not considered genetic engineering, are related and genetic engineering can be used within them. Synthetic biology is an emerging discipline that takes genetic engineering a step further by introducing artificially synthesised material into an organism. Plants, animals or micro organisms that have been changed through genetic engineering are termed genetically modified organisms or GMOs.
If genetic material from another species is added to the host, the resulting organism is called transgenic. If genetic material from the same species or a species that can breed with the host is used the resulting organism is called cisgenic. If genetic engineering is used to r