id int64 0 18.9k | biography stringlengths 151 1.51k | qa listlengths 1 25 |
|---|---|---|
17,732 | Since LED efficacy is inversely proportional to operating temperature, LED technology is well suited for supermarket freezer lighting. Because LEDs produce less waste heat than incandescent lamps, their use in freezers can save on refrigeration costs as well. However, they may be more susceptible to frost and snow buil... | [
{
"answer": "operating temperature",
"question": "LED efficacy is inversely proportional to what?"
},
{
"answer": "supermarket freezer",
"question": "Where is LED lighting very well suited?"
},
{
"answer": "incandescent lamps",
"question": "LEDs produce less waste heat than what othe... |
17,734 | In the late 1980s, key breakthroughs in GaN epitaxial growth and p-type doping ushered in the modern era of GaN-based optoelectronic devices. Building upon this foundation, Dr. Moustakas at Boston University patented a method for producing high-brightness blue LEDs using a new two-step process. Two years later, in 1993... | [
{
"answer": "1980s",
"question": "In what decade were breakthroughs made that brought in the modern era of GaN-based optoelectronic devices?"
},
{
"answer": "Shuji Nakamura",
"question": "Who first patented a method to produce high-brightness blue LEDs?"
},
{
"answer": "Dr. Moustakas",
... |
17,735 | Nakamura was awarded the 2006 Millennium Technology Prize for his invention. Nakamura, Hiroshi Amano and Isamu Akasaki were awarded the Nobel Prize in Physics in 2014 for the invention of the blue LED. In 2015, a US court ruled that three companies (i.e. the litigants who had not previously settled out of court) that h... | [
{
"answer": "Physics",
"question": "What Nobel Prize did Nakamura, Amano, and Akasaki receive in 2014?"
},
{
"answer": "Millennium Technology Prize",
"question": "What award did Nakamura receive in 2006 for his invention?"
},
{
"answer": "three",
"question": "How many companies did a... |
17,736 | By the late 1990s, blue LEDs became widely available. They have an active region consisting of one or more InGaN quantum wells sandwiched between thicker layers of GaN, called cladding layers. By varying the relative In/Ga fraction in the InGaN quantum wells, the light emission can in theory be varied from violet to am... | [
{
"answer": "active region consisting of one or more InGaN quantum wells sandwiched between thicker layers of GaN",
"question": "What are cladding layers?"
},
{
"answer": "By varying the relative In/Ga fraction in the InGaN quantum wells",
"question": "How can light emission be varied from viole... |
17,737 | With nitrides containing aluminium, most often AlGaN and AlGaInN, even shorter wavelengths are achievable. Ultraviolet LEDs in a range of wavelengths are becoming available on the market. Near-UV emitters at wavelengths around 375–395 nm are already cheap and often encountered, for example, as black light lamp replacem... | [
{
"answer": "aluminium",
"question": "What substance does nitrides contain?"
},
{
"answer": "Ultraviolet",
"question": "What sort of LEDs are becoming more available on the market?"
},
{
"answer": "375–395 nm",
"question": "What is the range of wavelengths for cheap UV LEDs?"
},
... |
17,738 | White light can be formed by mixing differently colored lights; the most common method is to use red, green, and blue (RGB). Hence the method is called multi-color white LEDs (sometimes referred to as RGB LEDs). Because these need electronic circuits to control the blending and diffusion of different colors, and becaus... | [
{
"answer": "red, green, and blue",
"question": "What colors are used to form white light?"
},
{
"answer": "multi-color white LEDs",
"question": "What is the method called that mixes red, green, and blue colors to form white light?"
},
{
"answer": "electronic circuits",
"question": "... |
17,739 | There are several types of multi-color white LEDs: di-, tri-, and tetrachromatic white LEDs. Several key factors that play among these different methods, include color stability, color rendering capability, and luminous efficacy. Often, higher efficiency will mean lower color rendering, presenting a trade-off between t... | [
{
"answer": "luminous efficacy",
"question": "What is a factor that may be different in the various types of multi-color white LEDs?"
},
{
"answer": "lower color rendering",
"question": "Higher efficiency in multi-color white LEDs may mean what?"
},
{
"answer": "tetrachromatic",
"que... |
17,740 | Multi-color LEDs offer not merely another means to form white light but a new means to form light of different colors. Most perceivable colors can be formed by mixing different amounts of three primary colors. This allows precise dynamic color control. As more effort is devoted to investigating this method, multi-color... | [
{
"answer": "to form light of different colors",
"question": "Multi-color LEDs offer what else besides the formation of white light?"
},
{
"answer": "power decays exponentially with rising temperature",
"question": "What problem must be solved before multi-color LEDs can play a role in the marke... |
17,741 | This method involves coating LEDs of one color (mostly blue LEDs made of InGaN) with phosphors of different colors to form white light; the resultant LEDs are called phosphor-based or phosphor-converted white LEDs (pcLEDs). A fraction of the blue light undergoes the Stokes shift being transformed from shorter wavelengt... | [
{
"answer": "phosphor-converted white LEDs (pcLEDs)",
"question": "What method involves coating LEDs of one color with phosphors of different colors?"
},
{
"answer": "blue",
"question": "In pcLEDs method, a fraction of what light is used?"
},
{
"answer": "Stokes",
"question": "What s... |
17,742 | Phosphor-based LED efficiency losses are due to the heat loss from the Stokes shift and also other phosphor-related degradation issues. Their luminous efficacies compared to normal LEDs depend on the spectral distribution of the resultant light output and the original wavelength of the LED itself. For example, the lumi... | [
{
"answer": "the spectral distribution of the resultant light output",
"question": "What do phosphor-based LEDs luminous efficacies depend on?"
},
{
"answer": "phosphor method",
"question": "What is the most popular method for making high-intensity white LEDs?"
},
{
"answer": "heat loss ... |
17,743 | Among the challenges being faced to improve the efficiency of LED-based white light sources is the development of more efficient phosphors. As of 2010, the most efficient yellow phosphor is still the YAG phosphor, with less than 10% Stoke shift loss. Losses attributable to internal optical losses due to re-absorption i... | [
{
"answer": "more efficient phosphors",
"question": "What can improve the efficiency of LED-based white light?"
},
{
"answer": "YAG phosphor",
"question": "What is the most efficient yellow phosphor?"
},
{
"answer": "less than 10%",
"question": "What is the percentage of stoke shift ... |
17,744 | White LEDs can also be made by coating near-ultraviolet (NUV) LEDs with a mixture of high-efficiency europium-based phosphors that emit red and blue, plus copper and aluminium-doped zinc sulfide (ZnS:Cu, Al) that emits green. This is a method analogous to the way fluorescent lamps work. This method is less efficient th... | [
{
"answer": "near-ultraviolet (NUV) LEDs",
"question": "White LEDs can be made by coating what?"
},
{
"answer": "copper and aluminium-doped zinc sulfide (ZnS:Cu, Al)",
"question": "What are near-ultraviolet LEDs coated with to create white LED?"
},
{
"answer": "fluorescent lamps",
"q... |
17,745 | A new style of wafers composed of gallium-nitride-on-silicon (GaN-on-Si) is being used to produce white LEDs using 200-mm silicon wafers. This avoids the typical costly sapphire substrate in relatively small 100- or 150-mm wafer sizes. The sapphire apparatus must be coupled with a mirror-like collector to reflect light... | [
{
"answer": "wafers composed of gallium-nitride-on-silicon",
"question": "What is being used to produce white LEDs?"
},
{
"answer": "200-mm",
"question": "What size are the wafers used to create white LEDs?"
},
{
"answer": "costly sapphire substrate",
"question": "By using silicon wa... |
17,746 | Quantum dots (QD) are semiconductor nanocrystals that possess unique optical properties. Their emission color can be tuned from the visible throughout the infrared spectrum. This allows quantum dot LEDs to create almost any color on the CIE diagram. This provides more color options and better color rendering than white... | [
{
"answer": "Quantum dots",
"question": "What nanocrystals possess unique optical properties?"
},
{
"answer": "create almost any color on the CIE diagram",
"question": "Quantum Dot LEDs can do what special skill?"
},
{
"answer": "better color rendering",
"question": "The narrowing of... |
17,747 | The structure of QD-LEDs used for the electrical-excitation scheme is similar to basic design of OLEDs. A layer of quantum dots is sandwiched between layers of electron-transporting and hole-transporting materials. An applied electric field causes electrons and holes to move into the quantum dot layer and recombine for... | [
{
"answer": "electrical-excitation",
"question": "What is one scheme of Quantum Dot excitation?"
},
{
"answer": "hole-transporting materials",
"question": "What is one material used in electrical-excitation?"
},
{
"answer": "electrons and holes",
"question": "During the electrical-ex... |
17,748 | High-power LEDs (HP-LEDs) or high-output LEDs (HO-LEDs) can be driven at currents from hundreds of mA to more than an ampere, compared with the tens of mA for other LEDs. Some can emit over a thousand lumens. LED power densities up to 300 W/cm2 have been achieved. Since overheating is destructive, the HP-LEDs must be m... | [
{
"answer": "over a thousand",
"question": "How many lumens can some high-power LEDs emit?"
},
{
"answer": "300 W/cm2",
"question": "Up to how many densities have been achieved with LED power?"
},
{
"answer": "to allow for heat dissipation",
"question": "Why must High-power LEDs be m... |
17,749 | LEDs have been developed by Seoul Semiconductor that can operate on AC power without the need for a DC converter. For each half-cycle, part of the LED emits light and part is dark, and this is reversed during the next half-cycle. The efficacy of this type of HP-LED is typically 40 lm/W. A large number of LED elements i... | [
{
"answer": "Seoul Semiconductor",
"question": "What company has developed LEDs that can operate on AC power?"
},
{
"answer": "40 lm/W",
"question": "What is the efficacy of an AC powered HP-LED?"
},
{
"answer": "2009",
"question": "When did Seoul Semiconductor release the first high... |
17,750 | Alphanumeric LEDs are available in seven-segment, starburst and dot-matrix format. Seven-segment displays handle all numbers and a limited set of letters. Starburst displays can display all letters. Dot-matrix displays typically use 5x7 pixels per character. Seven-segment LED displays were in widespread use in the 1970... | [
{
"answer": "Alphanumeric",
"question": "What type of LEDs are available in seven-segment format?"
},
{
"answer": "dot-matrix",
"question": "What is another format that Alphanumeric LEDs are available in?"
},
{
"answer": "Starburst",
"question": "Which alphanumeric LED display can di... |
17,751 | Digital-RGB LEDs are RGB LEDs that contain their own "smart" control electronics. In addition to power and ground, these provide connections for data-in, data-out, and sometimes a clock or strobe signal. These are connected in a daisy chain, with the data in of the first LED sourced by a microprocessor, which can contr... | [
{
"answer": "contain their own \"smart\" control electronics",
"question": "What makes RGB LEDs different?"
},
{
"answer": "in a daisy chain",
"question": "How are Digital-RGB LED strobe signals connected?"
},
{
"answer": "microprocessor",
"question": "What object sources the data in... |
17,752 | An LED filament consists of multiple LED dice connected in series on a common longitudinal substrate that form a thin rod reminiscent of a traditional incandescent filament. These are being used as a low cost decorative alternative for traditional light bulbs that are being phased out in many countries. The filaments r... | [
{
"answer": "multiple LED dice",
"question": "What does an LED filament consist of?"
},
{
"answer": "a low cost decorative alternative for traditional light bulbs",
"question": "How are LED filaments used?"
},
{
"answer": "high",
"question": "What type of voltage is needed for LED fi... |
17,753 | The current–voltage characteristic of an LED is similar to other diodes, in that the current is dependent exponentially on the voltage (see Shockley diode equation). This means that a small change in voltage can cause a large change in current. If the applied voltage exceeds the LED's forward voltage drop by a small am... | [
{
"answer": "the current is dependent exponentially on the voltage",
"question": "How are LEDs similar to other diodes?"
},
{
"answer": "use constant-current power supplies",
"question": "What is a solution to preventing an LED failure?"
},
{
"answer": "a small change in voltage",
"q... |
17,754 | The vast majority of devices containing LEDs are "safe under all conditions of normal use", and so are classified as "Class 1 LED product"/"LED Klasse 1". At present, only a few LEDs—extremely bright LEDs that also have a tightly focused viewing angle of 8° or less—could, in theory, cause temporary blindness, and so ar... | [
{
"answer": "Class 1 LED product",
"question": "How are most LEDs classified?"
},
{
"answer": "safe under all conditions of normal use",
"question": "What does being a Class 1 LED product mean?"
},
{
"answer": "extremely bright LEDs",
"question": "What type of LED can possibly cause ... |
17,755 | While LEDs have the advantage over fluorescent lamps that they do not contain mercury, they may contain other hazardous metals such as lead and arsenic. Regarding the toxicity of LEDs when treated as waste, a study published in 2011 stated: "According to federal standards, LEDs are not hazardous except for low-intensit... | [
{
"answer": "arsenic",
"question": "What dangerous metal can LEDs contain?"
},
{
"answer": "mercury",
"question": "What substance does fluorescent lamps contain?"
},
{
"answer": "low-intensity red",
"question": "Which LEDs are considered dangerous by a 2011 study?"
},
{
"answ... |
17,756 | One-color light is well suited for traffic lights and signals, exit signs, emergency vehicle lighting, ships' navigation lights or lanterns (chromacity and luminance standards being set under the Convention on the International Regulations for Preventing Collisions at Sea 1972, Annex I and the CIE) and LED-based Christ... | [
{
"answer": "One-color light",
"question": "What type of light is ideal for traffic signals?"
},
{
"answer": "1972",
"question": "In what year were luminescence standards set?"
},
{
"answer": "Red or yellow",
"question": "What color LEDs are used when night vision is important?"
},... |
17,757 | Because of their long life, fast switching times, and their ability to be seen in broad daylight due to their high output and focus, LEDs have been used in brake lights for cars' high-mounted brake lights, trucks, and buses, and in turn signals for some time, but many vehicles now use LEDs for their rear light clusters... | [
{
"answer": "brake lights for cars",
"question": "Because of their high output, LED lights are very useful where?"
},
{
"answer": "their long life",
"question": "Why are LED lights sought after for various applications?"
},
{
"answer": "0.5 second",
"question": "LED brake lights are ... |
17,758 | Assistive listening devices in many theaters and similar spaces use arrays of infrared LEDs to send sound to listeners' receivers. Light-emitting diodes (as well as semiconductor lasers) are used to send data over many types of fiber optic cable, from digital audio over TOSLINK cables to the very high bandwidth fiber l... | [
{
"answer": "theaters",
"question": "Where are infrared LEDs used in everday life?"
},
{
"answer": "to send sound to listeners' receivers",
"question": "How are LEDs used in theaters?"
},
{
"answer": "fiber optic",
"question": "LEDs can send data over what type of cable?"
},
{
... |
17,759 | In the US, one kilowatt-hour (3.6 MJ) of electricity currently causes an average 1.34 pounds (610 g) of CO
2 emission. Assuming the average light bulb is on for 10 hours a day, a 40-watt bulb will cause 196 pounds (89 kg) of CO
2 emission per year. The 6-watt LED equivalent will only cause 30 pounds (14 kg) of CO
2 ove... | [
{
"answer": "US",
"question": "In what country does one kilowatt-hour of electricity causes 1.34 pounds of CO 2 emission?"
},
{
"answer": "196 pounds",
"question": "How much CO2 emission would a 40-watt light bulb produce after 10 hours?"
},
{
"answer": "30 pounds",
"question": "A 6-... |
17,760 | Machine vision systems often require bright and homogeneous illumination, so features of interest are easier to process. LEDs are often used for this purpose, and this is likely to remain one of their major uses until the price drops low enough to make signaling and illumination uses more widespread. Barcode scanners a... | [
{
"answer": "Machine vision",
"question": "LEDs are often used for what type of systems?"
},
{
"answer": "so features of interest are easier to process",
"question": "Why are LEDs preferred for machine vision systems?"
},
{
"answer": "price drops",
"question": "What can help make LED... |
17,761 | The light from LEDs can be modulated very quickly so they are used extensively in optical fiber and free space optics communications. This includes remote controls, such as for TVs, VCRs, and LED Computers, where infrared LEDs are often used. Opto-isolators use an LED combined with a photodiode or phototransistor to pr... | [
{
"answer": "free space optics communications",
"question": "Where are LEDs often used?"
},
{
"answer": "medical equipment",
"question": "Where are opto-isolators found?"
},
{
"answer": "remote controls",
"question": "What is an example of a device that uses free space optic communic... |
17,762 | Many sensor systems rely on light as the signal source. LEDs are often ideal as a light source due to the requirements of the sensors. LEDs are used as motion sensors, for example in optical computer mice. The Nintendo Wii's sensor bar uses infrared LEDs. Pulse oximeters use them for measuring oxygen saturation. Some f... | [
{
"answer": "Nintendo Wii",
"question": "What video game console uses infrared LEDs?"
},
{
"answer": "Pulse oximeters",
"question": "What device uses infrared LEDs to measure oxygen saturation?"
},
{
"answer": "RGB LEDs",
"question": "Some flatbed scanners use what type of LED?"
},... |
17,763 | LEDs have also been used as a medium-quality voltage reference in electronic circuits. The forward voltage drop (e.g. about 1.7 V for a normal red LED) can be used instead of a Zener diode in low-voltage regulators. Red LEDs have the flattest I/V curve above the knee. Nitride-based LEDs have a fairly steep I/V curve an... | [
{
"answer": "medium-quality",
"question": "What quality has LEDs been used as?"
},
{
"answer": "Red",
"question": "What LED has the flattest I/V curve above the knee?"
},
{
"answer": "Nitride-based LEDs",
"question": "What LEDs have a very steep I/V curve?"
},
{
"answer": "Ze... |
17,764 | Birds (Aves) are a group of endothermic vertebrates, characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a lightweight but strong skeleton. Birds live worldwide and range in size from the 5 cm (2 in) bee hummingbird to the 2.75 m (9 ft) o... | [
{
"answer": "Birds",
"question": "What is a group of endothermic vertebrates characterised by feathers and toothless beaked jaws?"
},
{
"answer": "bee hummingbird",
"question": "What is the smallest bird?"
},
{
"answer": "ostrich",
"question": "What is the largest bird?"
},
{
... |
17,765 | The fossil record indicates that birds are the last surviving dinosaurs, having evolved from feathered ancestors within the theropod group of saurischian dinosaurs. True birds first appeared during the Cretaceous period, around 100 million years ago. DNA-based evidence finds that birds diversified dramatically around t... | [
{
"answer": "birds",
"question": "What are the last surviving dinosaurs, according o the fossil record?"
},
{
"answer": "Cretaceous period",
"question": "When did true birds first appear?"
},
{
"answer": "Archaeopteryx",
"question": "Name an example of an early stem-bird."
}
] |
17,766 | Birds have wings which are more or less developed depending on the species; the only known groups without wings are the extinct moas and elephant birds. Wings, which evolved from forelimbs, give most birds the ability to fly, although further speciation has led to some flightless birds, including ratites, penguins, and... | [
{
"answer": "digestive and respiratory systems",
"question": "What makes birds uniquely adapted for flight?"
},
{
"answer": "Darwin's finches",
"question": "What type of bird particularly played an important part in the inception of Darwin's theory of evolution by natural selection?"
},
{
... |
17,767 | Some birds, especially corvids and parrots, are among the most intelligent animals; several bird species make and use tools, and many social species pass on knowledge across generations, which is considered a form of culture. Many species annually migrate great distances. Birds are social, communicating with visual sig... | [
{
"answer": "corvids and parrots",
"question": "Which type of birds are among the most intelligent animals?"
},
{
"answer": "by laying eggs which are fertilized through sexual reproduction",
"question": "How to birds produce offspring?"
},
{
"answer": "nest",
"question": "Where are e... |
17,768 | Many species of birds are economically important. Domesticated and undomesticated birds (poultry and game) are important sources of eggs, meat, and feathers. Songbirds, parrots, and other species are popular as pets. Guano (bird excrement) is harvested for use as a fertilizer. Birds prominently figure throughout human ... | [
{
"answer": "Songbirds, parrots",
"question": "Which birds are popular as pets?"
},
{
"answer": "bird excrement",
"question": "What is guano?"
},
{
"answer": "Guano",
"question": "What is the name of bird excrement?"
},
{
"answer": "Guano",
"question": "What is harvested ... |
17,769 | Aves and a sister group, the clade Crocodilia, contain the only living representatives of the reptile clade Archosauria. During the late 1990s, Aves was most commonly defined phylogenetically as all descendants of the most recent common ancestor of modern birds and Archaeopteryx lithographica. However, an earlier defin... | [
{
"answer": "clade Crocodilia",
"question": "Besides Aves, what group contains the only living representatives of the reptile clade Archosauria?"
},
{
"answer": "Gauthier",
"question": "Who defined Aves to include only the crown group of the set of modern birds?"
},
{
"answer": "clade Cr... |
17,770 | Based on fossil and biological evidence, most scientists accept that birds are a specialized subgroup of theropod dinosaurs, and more specifically, they are members of Maniraptora, a group of theropods which includes dromaeosaurs and oviraptorids, among others. As scientists have discovered more theropods closely relat... | [
{
"answer": "fossil and biological evidence",
"question": "What evidence leads most scientists to accept that birds are a specialized subgroup of theropod dinosaurs?"
},
{
"answer": "Maniraptora",
"question": "What is a group of theropods which include dromaeosaurs and oviraptorids?"
},
{
... |
17,771 | The consensus view in contemporary paleontology is that the flying theropods, or avialans, are the closest relatives of the deinonychosaurs, which include dromaeosaurids and troodontids. Together, these form a group called Paraves. Some basal members of this group, such as Microraptor, have features which may have enab... | [
{
"answer": "flying theropods",
"question": "What are the closest relatives of the deinonychosaurs?"
},
{
"answer": "deinonychosaurs",
"question": "What are the closest relatives of flying theropods?"
},
{
"answer": "deinonychosaurs",
"question": "Dromaeosaurids and troodontids are m... |
17,772 | The Late Jurassic Archaeopteryx is well known as one of the first transitional fossils to be found, and it provided support for the theory of evolution in the late 19th century. Archaeopteryx was the first fossil to display both clearly traditional reptilian characteristics: teeth, clawed fingers, and a long, lizard-li... | [
{
"answer": "Late Jurassic Archaeopteryx",
"question": "What is known as one of the first transitional fossils to be found?"
},
{
"answer": "Archaeopteryx",
"question": "What was the first fossil to display both clearly traditional reptilian characteristics?"
},
{
"answer": "reptilian",
... |
17,773 | The earliest known avialan fossils come from the Tiaojishan Formation of China, which has been dated to the late Jurassic period (Oxfordian stage), about 160 million years ago. The avialan species from this time period include Anchiornis huxleyi, Xiaotingia zhengi, and Aurornis xui. The well-known early avialan, Archae... | [
{
"answer": "late Jurassic period",
"question": "The Oxfordian stage is also known as what?"
},
{
"answer": "about 160 million years ago",
"question": "How long ago was the late Jurassic period?"
},
{
"answer": "hind wings",
"question": "What may have been used in aerial maneuvering?... |
17,774 | Avialans diversified into a wide variety of forms during the Cretaceous Period. Many groups retained primitive characteristics, such as clawed wings and teeth, though the latter were lost independently in a number of avialan groups, including modern birds (Aves). While the earliest forms, such as Archaeopteryx and Jeho... | [
{
"answer": "Cretaceous Period",
"question": "During which time period did avialans diversify into a wide variety of forms?"
},
{
"answer": "Archaeopteryx and Jeholornis",
"question": "Which forms retained the long bony tails of their ancestors?"
},
{
"answer": "late Cretaceous",
"qu... |
17,775 | The first large, diverse lineage of short-tailed avialans to evolve were the enantiornithes, or "opposite birds", so named because the construction of their shoulder bones was in reverse to that of modern birds. Enantiornithes occupied a wide array of ecological niches, from sand-probing shorebirds and fish-eaters to t... | [
{
"answer": "enantiornithes",
"question": "What were the first large, diverse lineage of short-tailed avialans to evolve?"
},
{
"answer": "opposite birds",
"question": "Because of the construction of their shoulder bones, what were the enantiornithes called?"
},
{
"answer": "enantiornith... |
17,776 | Many species of the second major avialan lineage to diversify, the Euornithes (meaning "true birds", because they include the ancestors of modern birds), were semi-aquatic and specialized in eating fish and other small aquatic organisms. Unlike the enantiornithes, which dominated land-based and arboreal habitats, most ... | [
{
"answer": "Euornithes",
"question": "What group became the first avialans to develop true pygostyle and a fully mobile fan of tail feathers?"
},
{
"answer": "true birds",
"question": "What does Euornithes mean?"
},
{
"answer": "because they include the ancestors of modern birds",
"... |
17,777 | All modern birds lie within the crown group Aves (alternately Neornithes), which has two subdivisions: the Palaeognathae, which includes the flightless ratites (such as the ostriches) and the weak-flying tinamous, and the extremely diverse Neognathae, containing all other birds. These two subdivisions are often given t... | [
{
"answer": "Aves",
"question": "All modern birds lie within which crown group?"
},
{
"answer": "Neornithes",
"question": "What is another name for Aves?"
},
{
"answer": "Aves",
"question": "The two subdivisions of what group include Palaeognathae and Neognathae?"
},
{
"answe... |
17,779 | The classification of birds is a contentious issue. Sibley and Ahlquist's Phylogeny and Classification of Birds (1990) is a landmark work on the classification of birds, although it is frequently debated and constantly revised. Most evidence seems to suggest the assignment of orders is accurate, but scientists disagree... | [
{
"answer": "birds",
"question": "Sibley and Ahlquist' Phylogeny and Classification of Birds is a landmark work on the classification of what animals?"
},
{
"answer": "relationships between the orders themselves",
"question": "What do scientists disagree about?"
},
{
"answer": "the assig... |
17,780 | Birds live and breed in most terrestrial habitats and on all seven continents, reaching their southern extreme in the snow petrel's breeding colonies up to 440 kilometres (270 mi) inland in Antarctica. The highest bird diversity occurs in tropical regions. It was earlier thought that this high diversity was the result ... | [
{
"answer": "seven",
"question": "Birds live on how many continents?"
},
{
"answer": "tropical",
"question": "Highest bird diversity occurs in which regions?"
},
{
"answer": "980",
"question": "Some penguins have been recording diving up to how many feet?"
},
{
"answer": "to ... |
17,781 | Many bird species have established breeding populations in areas to which they have been introduced by humans. Some of these introductions have been deliberate; the ring-necked pheasant, for example, has been introduced around the world as a game bird. Others have been accidental, such as the establishment of wild monk... | [
{
"answer": "game bird",
"question": "The ring-necked pheasant has been introduced as what kind of bird?"
},
{
"answer": "agricultural practices created suitable new habitat",
"question": "Why have some species spread naturally far beyond their original ranges?"
},
{
"answer": "in areas ... |
17,782 | The skeleton consists of very lightweight bones. They have large air-filled cavities (called pneumatic cavities) which connect with the respiratory system. The skull bones in adults are fused and do not show cranial sutures. The orbits are large and separated by a bony septum. The spine has cervical, thoracic, lumbar a... | [
{
"answer": "The skeleton",
"question": "What consists of very lightweight bones?"
},
{
"answer": "very lightweight bones",
"question": "What does the skeleton consist of?"
},
{
"answer": "large air-filled cavities",
"question": "What are pneumatic cavities?"
},
{
"answer": "... |
17,784 | Birds have one of the most complex respiratory systems of all animal groups. Upon inhalation, 75% of the fresh air bypasses the lungs and flows directly into a posterior air sac which extends from the lungs and connects with air spaces in the bones and fills them with air. The other 25% of the air goes directly into th... | [
{
"answer": "75%",
"question": "Upon inhalation, what percentage of fresh air bypasses the lungs and flows directly into a posterior air sac?"
},
{
"answer": "directly into the lungs",
"question": "Where does the other 25 percent of fresh air go?"
},
{
"answer": "a muscular chamber incor... |
17,787 | The nervous system is large relative to the bird's size. The most developed part of the brain is the one that controls the flight-related functions, while the cerebellum coordinates movement and the cerebrum controls behaviour patterns, navigation, mating and nest building. Most birds have a poor sense of smell with no... | [
{
"answer": "nervous system",
"question": "Which bird system is large relative to a bird's size?"
},
{
"answer": "possessing ultraviolet (UV) sensitive cone cells in the eye as well as green, red and blue ones",
"question": "What is tetrachromatic?"
},
{
"answer": "courtship",
"quest... |
17,789 | A dearth of field observations limit our knowledge, but intraspecific conflicts are known to sometimes result in injury or death. The screamers (Anhimidae), some jacanas (Jacana, Hydrophasianus), the spur-winged goose (Plectropterus), the torrent duck (Merganetta) and nine species of lapwing (Vanellus) use a sharp spur... | [
{
"answer": "intraspecific conflicts",
"question": "What is known to sometimes result in injury or death?"
},
{
"answer": "Tachyeres",
"question": "What is another name for steamer ducks?"
},
{
"answer": "screamers",
"question": "What is another name for Anhimidae?"
},
{
"ans... |
17,790 | Feathers are a feature characteristic of birds (though also present in some dinosaurs not currently considered to be true birds). They facilitate flight, provide insulation that aids in thermoregulation, and are used in display, camouflage, and signaling. There are several types of feathers, each serving its own set of... | [
{
"answer": "Feathers",
"question": "What is a feature characteristic of birds?"
},
{
"answer": "Feathers",
"question": "What feature of a bird facilitate flight?"
},
{
"answer": "specific tracts of skin",
"question": "What is pterylae?"
}
] |
17,792 | Feathers require maintenance and birds preen or groom them daily, spending an average of around 9% of their daily time on this. The bill is used to brush away foreign particles and to apply waxy secretions from the uropygial gland; these secretions protect the feathers' flexibility and act as an antimicrobial agent, in... | [
{
"answer": "daily",
"question": "How often do birds groom their feathers?"
},
{
"answer": "9%",
"question": "What percentage of their day do birds groom their feathers?"
},
{
"answer": "The bill",
"question": "What do birds use to brush away foreign particles?"
},
{
"answer"... |
17,793 | Most birds can fly, which distinguishes them from almost all other vertebrate classes. Flight is the primary means of locomotion for most bird species and is used for breeding, feeding, and predator avoidance and escape. Birds have various adaptations for flight, including a lightweight skeleton, two large flight muscl... | [
{
"answer": "Most birds can fly,",
"question": "What distinguishes birds from almost all other vertebrate classes?"
},
{
"answer": "Flight",
"question": "What is the primary means of locomotion for most bird species?"
},
{
"answer": "two",
"question": "How many large flight muscles d... |
17,794 | Birds that employ many strategies to obtain food or feed on a variety of food items are called generalists, while others that concentrate time and effort on specific food items or have a single strategy to obtain food are considered specialists. Birds' feeding strategies vary by species. Many birds glean for insects, i... | [
{
"answer": "generalists",
"question": "What is the term used for birds that employ many strategies to obtain food?"
},
{
"answer": "specialists",
"question": "What is the term used for birds that concentrate time and effort on specific food items?"
},
{
"answer": "Nectar feeders",
"... |
17,795 | Some species, including frigatebirds, gulls, and skuas, engage in kleptoparasitism, stealing food items from other birds. Kleptoparasitism is thought to be a supplement to food obtained by hunting, rather than a significant part of any species' diet; a study of great frigatebirds stealing from masked boobies estimated ... | [
{
"answer": "kleptoparasitism",
"question": "What is the term for stealing food items from other birds?"
},
{
"answer": "stealing food items from other birds",
"question": "What is kleptoparasitism?"
},
{
"answer": "scavengers",
"question": "A vulture is what type of bird?"
}
] |
17,796 | Most birds scoop water in their beaks and raise their head to let water run down the throat. Some species, especially of arid zones, belonging to the pigeon, finch, mousebird, button-quail and bustard families are capable of sucking up water without the need to tilt back their heads. Some desert birds depend on water s... | [
{
"answer": "wetting their belly feathers",
"question": "How do nesting sandgrouse carry water to their young?"
},
{
"answer": "The pigeon family",
"question": "What is one family of birds have adaptations to produce a nutritive fluid to their chicks?"
},
{
"answer": "crop milk",
"qu... |
17,797 | Feathers being critical to the survival of a bird, require maintenance. Apart from physical wear and tear, feathers face the onslaught of fungi, ectoparasitic feather mites and birdlice. The physical condition of feathers are maintained by preening often with the application of secretions from the preen gland. Birds al... | [
{
"answer": "preen gland",
"question": "Birds preen often with the application of secretions from which gland?"
},
{
"answer": "water or dust",
"question": "What do birds bathe in?"
},
{
"answer": "bird encourages ants to run through their plumage",
"question": "What is anting?"
},... |
17,800 | The ability of birds to return to precise locations across vast distances has been known for some time; in an experiment conducted in the 1950s a Manx shearwater released in Boston returned to its colony in Skomer, Wales, within 13 days, a distance of 5,150 km (3,200 mi). Birds navigate during migration using a variety... | [
{
"answer": "diurnal migrants",
"question": "In which type of migration do birds use the sun to navigate by day and a stellar compass at night?"
},
{
"answer": "the Earth's geomagnetism",
"question": "Some species use specialised photoreceptors to sense what?"
},
{
"answer": "internal cl... |
17,801 | Birds sometimes use plumage to assess and assert social dominance, to display breeding condition in sexually selected species, or to make threatening displays, as in the sunbittern's mimicry of a large predator to ward off hawks and protect young chicks. Variation in plumage also allows for the identification of birds,... | [
{
"answer": "Variation in plumage",
"question": "What allows for the identification of birds, particularly between species?"
},
{
"answer": "plumage",
"question": "What do birds sometimes use to assess and assert social dominance?"
},
{
"answer": "ritualised displays",
"question": "V... |
17,802 | Calls are used for a variety of purposes, including mate attraction, evaluation of potential mates, bond formation, the claiming and maintenance of territories, the identification of other individuals (such as when parents look for chicks in colonies or when mates reunite at the start of breeding season), and the warni... | [
{
"answer": "mechanical sounds",
"question": "What do some birds use for auditory communication?"
},
{
"answer": "Calls",
"question": "What do birds use for evaluation of potential mates and mate attraction?"
},
{
"answer": "woodpeckers",
"question": "Which birds drum territorially?"... |
17,803 | While some birds are essentially territorial or live in small family groups, other birds may form large flocks. The principal benefits of flocking are safety in numbers and increased foraging efficiency. Defence against predators is particularly important in closed habitats like forests, where ambush predation is commo... | [
{
"answer": "safety in numbers and increased foraging efficiency",
"question": "What are the principal benefits of flocking?"
},
{
"answer": "bullying of socially subordinate birds by more dominant birds",
"question": "What is a cost of flocking?"
},
{
"answer": "Defence against predator... |
17,804 | The high metabolic rates of birds during the active part of the day is supplemented by rest at other times. Sleeping birds often use a type of sleep known as vigilant sleep, where periods of rest are interspersed with quick eye-opening "peeks", allowing them to be sensitive to disturbances and enable rapid escape from ... | [
{
"answer": "vigilant sleep",
"question": "Sleeping birds often use a type of sleep known as what?"
},
{
"answer": "Swifts",
"question": "What are believed to be able to sleep in flight?"
},
{
"answer": "because it lowers the loss of body heat",
"question": "Why is communal roosting ... |
17,805 | Many sleeping birds bend their heads over their backs and tuck their bills in their back feathers, although others place their beaks among their breast feathers. Many birds rest on one leg, while some may pull up their legs into their feathers, especially in cold weather. Perching birds have a tendon locking mechanism ... | [
{
"answer": "Perching birds",
"question": "These types of birds have a tendon locking mechanism."
},
{
"answer": "in trees",
"question": "Where do many ground birds, such as quails and pheasants, roost?"
},
{
"answer": "Loriculus",
"question": "A few parrots of what genus roost hangi... |
17,806 | Ninety-five percent of bird species are socially monogamous. These species pair for at least the length of the breeding season or—in some cases—for several years or until the death of one mate. Monogamy allows for both paternal care and biparental care, which is especially important for species in which females require... | [
{
"answer": "Ninety-five percent",
"question": "What percent of bird species are socially monogamous?"
},
{
"answer": "sperm storage mechanisms",
"question": "What do female birds have that allow sperm from males to remain viable long after copulation?"
},
{
"answer": "infidelity",
"... |
17,807 | Breeding usually involves some form of courtship display, typically performed by the male. Most displays are rather simple and involve some type of song. Some displays, however, are quite elaborate. Depending on the species, these may include wing or tail drumming, dancing, aerial flights, or communal lekking. Females ... | [
{
"answer": "male",
"question": "Which gender typically performs some form of courtship display?"
},
{
"answer": "song",
"question": "Most courtship displays involve some type of what?"
},
{
"answer": "Females",
"question": "Which gender generally drive partner selection?:"
},
{
... |
17,808 | All birds lay amniotic eggs with hard shells made mostly of calcium carbonate. Hole and burrow nesting species tend to lay white or pale eggs, while open nesters lay camouflaged eggs. There are many exceptions to this pattern, however; the ground-nesting nightjars have pale eggs, and camouflage is instead provided by t... | [
{
"answer": "amniotic eggs",
"question": "What kind of eggs to all birds lay?"
},
{
"answer": "calcium carbonate",
"question": "All birds lay eggs with hard shells made mostly out of what?"
},
{
"answer": "Hole and burrow nesting species",
"question": "What type of birds lay white or... |
17,809 | Bird eggs are usually laid in a nest. Most species create somewhat elaborate nests, which can be cups, domes, plates, beds scrapes, mounds, or burrows. Some bird nests, however, are extremely primitive; albatross nests are no more than a scrape on the ground. Most birds build nests in sheltered, hidden areas to avoid p... | [
{
"answer": "nest",
"question": "Where do birds usually lay their eggs?"
},
{
"answer": "cliff-nesting common guillemot",
"question": "What type of birds lay its eggs on bare rock?"
},
{
"answer": "between their body and feet",
"question": "Where do male emporer penguins keep eggs?"
... |
17,810 | Incubation, which optimises temperature for chick development, usually begins after the last egg has been laid. In monogamous species incubation duties are often shared, whereas in polygamous species one parent is wholly responsible for incubation. Warmth from parents passes to the eggs through brood patches, areas of ... | [
{
"answer": "Incubation",
"question": "What process optimises temperature for chick development?"
},
{
"answer": "after the last egg has been laid",
"question": "When does incubation begin?"
},
{
"answer": "brood patches",
"question": "What are areas of bare skin on the abdomen or br... |
17,811 | The length and nature of parental care varies widely amongst different orders and species. At one extreme, parental care in megapodes ends at hatching; the newly hatched chick digs itself out of the nest mound without parental assistance and can fend for itself immediately. At the other extreme, many seabirds have exte... | [
{
"answer": "at hatching",
"question": "When does parental care end in megapodes?"
},
{
"answer": "frigatebird",
"question": "What type of seabird has the longest period of parental care?"
},
{
"answer": "chick guard stage",
"question": "What is the period of breeding during which on... |
17,812 | In some species, both parents care for nestlings and fledglings; in others, such care is the responsibility of only one sex. In some species, other members of the same species—usually close relatives of the breeding pair, such as offspring from previous broods—will help with the raising of the young. Such alloparenting... | [
{
"answer": "Corvida",
"question": "Alloparenting is particulary common with what species?"
},
{
"answer": "Corvida",
"question": "True crows belong to what group?"
},
{
"answer": "male parental care",
"question": "What is more common in birds than any other vertebrate class?"
}
] |
17,813 | The point at which chicks fledge varies dramatically. The chicks of the Synthliboramphus murrelets, like the ancient murrelet, leave the nest the night after they hatch, following their parents out to sea, where they are raised away from terrestrial predators. Some other species, such as ducks, move their chicks away f... | [
{
"answer": "chicks of the Synthliboramphus murrelets",
"question": "Which chicks leave the nest the night after they hatch?"
},
{
"answer": "ducks",
"question": "Name a species which move their chicks away from the nest at an early age."
},
{
"answer": "just before, or soon after, they ... |
17,814 | Brood parasitism, in which an egg-layer leaves her eggs with another individual's brood, is more common among birds than any other type of organism. After a parasitic bird lays her eggs in another bird's nest, they are often accepted and raised by the host at the expense of the host's own brood. Brood parasites may be ... | [
{
"answer": "Brood parasitism",
"question": "What is it called when an egg-layer leaves her eggs with another individual's brood?"
},
{
"answer": "One hundred",
"question": "How many bird species are obligate parasites?"
},
{
"answer": "non-obligate brood parasites",
"question": "Wha... |
17,815 | Birds have evolved a variety of mating behaviors, with the peacock tail being perhaps the most famous example of sexual selection and the Fisherian runaway. Commonly occurring sexual dimorphisms such as size and color differences are energetically costly attributes that signal competitive breeding situations. Many type... | [
{
"answer": "peacock tail",
"question": "What is the most famous example of sexual selection?"
},
{
"answer": "female choice",
"question": "What is intersexual selection also known as?"
},
{
"answer": "intrasexual competition",
"question": "What is it called when individuals of the m... |
17,816 | Incestuous matings by the purple-crowned fairy wren Malurus coronatus result in severe fitness costs due to inbreeding depression (greater than 30% reduction in hatchability of eggs). Females paired with related males may undertake extra pair matings (see Promiscuity#Other animals for 90% frequency in avian species) th... | [
{
"answer": "inbreeding depression",
"question": "What is it called when there is greater than 30 percent reduction in hatchability of eggs?"
},
{
"answer": "Females paired with related males may undertake extra pair matings",
"question": "What can reduce the negative effects of inbreeding?"
}... |
17,817 | Cooperative breeding in birds typically occurs when offspring, usually males, delay dispersal from their natal group in order to remain with the family to help rear younger kin. Female offspring rarely stay at home, dispersing over distances that allow them to breed independently, or to join unrelated groups. In genera... | [
{
"answer": "Cooperative breeding",
"question": "What occurs when offspring delay dispersal from their natal group?"
},
{
"answer": "Cross-fertilization between unrelated individuals",
"question": "What leads to the masking of deleterious recesive alleles in progeny?"
},
{
"answer": "bec... |
17,818 | Birds occupy a wide range of ecological positions. While some birds are generalists, others are highly specialised in their habitat or food requirements. Even within a single habitat, such as a forest, the niches occupied by different species of birds vary, with some species feeding in the forest canopy, others beneath... | [
{
"answer": "Aquatic birds",
"question": "What type of birds generally feed by fishing, plant eating or piracy?"
},
{
"answer": "Forest birds",
"question": "What type of birds may be either insectivores, frugivores and nectarivores?"
},
{
"answer": "Birds of prey",
"question": "What ... |
17,819 | Birds are often important to island ecology. Birds have frequently reached islands that mammals have not; on those islands, birds may fulfill ecological roles typically played by larger animals. For example, in New Zealand the moas were important browsers, as are the kereru and kokako today. Today the plants of New Zea... | [
{
"answer": "Birds",
"question": "What are often important to island ecology?"
},
{
"answer": "moas",
"question": "In New Zealand, what were important browsers, as the kereru and kokako are today?"
},
{
"answer": "Nesting seabirds",
"question": "What type of birds may also affect the... |
17,820 | Since birds are highly visible and common animals, humans have had a relationship with them since the dawn of man. Sometimes, these relationships are mutualistic, like the cooperative honey-gathering among honeyguides and African peoples such as the Borana. Other times, they may be commensal, as when species such as th... | [
{
"answer": "commensal",
"question": "What is it called when the house sparrow has benefited from human activity?"
},
{
"answer": "Human activities",
"question": "What have threatened numerous bird species with extinction?"
},
{
"answer": "Since birds are highly visible and common animal... |
17,821 | Domesticated birds raised for meat and eggs, called poultry, are the largest source of animal protein eaten by humans; in 2003, 76 million tons of poultry and 61 million tons of eggs were produced worldwide. Chickens account for much of human poultry consumption, though domesticated turkeys, ducks, and geese are also r... | [
{
"answer": "poultry",
"question": "What are domesticated birds raised for meat and eggs?"
},
{
"answer": "poultry",
"question": "What is the largest source of animal protein eaten by humans?"
},
{
"answer": "76 million tons",
"question": "In 2003, how many tons of poultry were produ... |
17,822 | Birds have been domesticated by humans both as pets and for practical purposes. Colourful birds, such as parrots and mynas, are bred in captivity or kept as pets, a practice that has led to the illegal trafficking of some endangered species. Falcons and cormorants have long been used for hunting and fishing, respective... | [
{
"answer": "both as pets and for practical purposes",
"question": "Why have birds been domesticated by humans?"
},
{
"answer": "Colourful birds",
"question": "What type of birds are bred in captivity or kept as pets?"
},
{
"answer": "since at least 1 AD",
"question": "How long have ... |
17,825 | Though human activities have allowed the expansion of a few species, such as the barn swallow and European starling, they have caused population decreases or extinction in many other species. Over a hundred bird species have gone extinct in historical times, although the most dramatic human-caused avian extinctions, er... | [
{
"answer": "Over a hundred",
"question": "How many bird species have gone extinct in historical times?"
},
{
"answer": "1,227",
"question": "How many species are listed as threatened by BirdLife International and the IUCN?"
},
{
"answer": "during the human colonisation of Melanesian, Po... |
17,826 | The Qing dynasty (Chinese: 清朝; pinyin: Qīng Cháo; Wade–Giles: Ch'ing Ch'ao; IPA: [tɕʰíŋ tʂʰɑ̌ʊ̯]), officially the Great Qing (Chinese: 大清; pinyin: Dà Qīng), also called the Empire of the Great Qing, or the Manchu dynasty, was the last imperial dynasty of China, ruling from 1644 to 1912 with a brief, abortive restoratio... | [
{
"answer": "Great Qing, or the Manchu dynasty",
"question": "What was the last Chinese dynasty?"
},
{
"answer": "1644 to 1912",
"question": "When did the Manchu dynasty rule?"
},
{
"answer": "Ming",
"question": "What was the dynasty that ruled before the Manchu?"
},
{
"answe... |
17,829 | After agreeing to sign the Boxer Protocol the government then initiated unprecedented fiscal and administrative reforms, including elections, a new legal code, and abolition of the examination system. Sun Yat-sen and other revolutionaries competed with reformers such as Liang Qichao and monarchists such as Kang Youwei ... | [
{
"answer": "Xinhai Revolution",
"question": "What started on October 11, 1911?"
},
{
"answer": "Puyi",
"question": "Who was the last Qing emperor?"
},
{
"answer": "February 12, 1912",
"question": "When did he step down?"
}
] |
17,832 | The Qing dynasty was founded not by Han Chinese, who constitute the majority of the Chinese population, but by a sedentary farming people known as the Jurchen, a Tungusic people who lived around the region now comprising the Chinese provinces of Jilin and Heilongjiang. The Manchus are sometimes mistaken for a nomadic p... | [
{
"answer": "Han Chinese",
"question": "What ethnic group make up the most people in China?"
},
{
"answer": "Jurchen",
"question": "Who founded the Qing dynasty?"
},
{
"answer": "sedentary farming",
"question": "What type of lifestyle did the Jurchen live?"
},
{
"answer": "Ji... |
17,833 | Relocating his court from Jianzhou to Liaodong provided Nurhachi access to more resources; it also brought him in close contact with the Khorchin Mongol domains on the plains of Mongolia. Although by this time the once-united Mongol nation had long since fragmented into individual and hostile tribes, these tribes still... | [
{
"answer": "Liaodong",
"question": "Where did Nurhachi move his court to?"
},
{
"answer": "Jianzhou",
"question": "Where did Nurhachi move his court from?"
},
{
"answer": "Mongol nation",
"question": "Who posed a threat to the Chinese borders?"
}
] |
17,834 | There were too few ethnic Manchus to conquer China, so they gained strength by defeating and absorbing Mongols, but more importantly, adding Han Chinese to the Eight Banners. The Manchus had to create an entire "Jiu Han jun" (Old Han Army) due to the massive amount of Han Chinese soldiers which were absorbed into the E... | [
{
"answer": "Mongols",
"question": "What group did the Manchus take over to add strength to their numbers?"
},
{
"answer": "artillery",
"question": "What weapon helped the Ming defeat the Manchus?"
},
{
"answer": "1641",
"question": "When did the Manchus create their own artillery?"
... |
17,835 | This was followed by the creation of the first two Han Banners in 1637 (increasing to eight in 1642). Together these military reforms enabled Hong Taiji to resoundingly defeat Ming forces in a series of battles from 1640 to 1642 for the territories of Songshan and Jinzhou. This final victory resulted in the surrender o... | [
{
"answer": "1637",
"question": "When were the first couple Han Banners founded?"
},
{
"answer": "1642",
"question": "When did the Han Banners grow to eight?"
},
{
"answer": "Chongzhen Emperor",
"question": "Who killed Yuan Chonghuan?"
},
{
"answer": "Hong Taiji",
"questi... |
17,837 | Hong Taiji died suddenly in September 1643 without a designated heir. As the Jurchens had traditionally "elected" their leader through a council of nobles, the Qing state did not have in place a clear succession system until the reign of the Kangxi Emperor. The leading contenders for power at this time were Hong Taiji'... | [
{
"answer": "September 1643",
"question": "When did Hong Taiji die?"
},
{
"answer": "without a designated heir",
"question": "Who was his heir?"
},
{
"answer": "Hong Taiji's oldest son Hooge and Hong Taiji' half brother Dorgon",
"question": "Who were the likely heirs?"
},
{
"... |
17,838 | Ming government officials fought against each other, against fiscal collapse, and against a series of peasant rebellions. They were unable to capitalise on the Manchu succession dispute and installation of a minor as emperor. In April 1644, the capital at Beijing was sacked by a coalition of rebel forces led by Li Zich... | [
{
"answer": "Li Zicheng",
"question": "Who raided Beijing in 1644?"
},
{
"answer": "former minor Ming official",
"question": "Who was Li Zicheng?"
},
{
"answer": "Chongzhen Emperor",
"question": "Who was the last Ming leader?"
},
{
"answer": "Shun",
"question": "What dyna... |
17,839 | Li Zicheng then led a coalition of rebel forces numbering 200,000[a] to confront Wu Sangui, the general commanding the Ming garrison at Shanhai Pass. Shanhai Pass is a pivotal pass of the Great Wall, located fifty miles northeast of Beijing, and for years its defenses kept the Manchus from directly raiding the Ming cap... | [
{
"answer": "200,000",
"question": "How big was Li Zicheng's army?"
},
{
"answer": "Wu Sangui",
"question": "Who did Li Zicheng's army fight?"
},
{
"answer": "Wu Sangui",
"question": "What was the name of the general at the Ming fort?"
},
{
"answer": "Wu and Dorgon",
"que... |
17,840 | The newly allied armies captured Beijing on June 6. The Shunzhi Emperor was invested as the "Son of Heaven" on October 30. The Manchus, who had positioned themselves as political heir to the Ming emperor by defeating the rebel Li Zicheng, completed the symbolic transition by holding a formal funeral for the Chongzhen E... | [
{
"answer": "seventeen years",
"question": "How long did it take for the Manchus to take the rest of China?"
},
{
"answer": "Ming loyalists",
"question": "Who did the Manchus struggle against?"
},
{
"answer": "October 30",
"question": "When did the Shunzhi emperor become the Son of H... |
17,841 | Han Chinese Banners were made up of Han Chinese who defected to the Qing up to 1644 and joined the Eight Banners, giving them social and legal privileges in addition to being acculturated to Manchu culture. So many Han defected to the Qing and swelled the ranks of the Eight Banners that ethnic Manchus became a minority... | [
{
"answer": "75%",
"question": "What percent of bannermen did the Han represent?"
},
{
"answer": "Han Chinese",
"question": "Who made up the Han Chinese Banners?"
},
{
"answer": "Mongol",
"question": "Who besides the Manchus and the Han made up the Eight Banners?"
}
] |
17,842 | The Qing showed that the Manchus valued military skills in propaganda targeted towards the Ming military to get them to defect to the Qing, since the Ming civilian political system discriminated against the military. The three Liaodong Han Bannermen officers who played a massive role in the conquest of southern China f... | [
{
"answer": "Shang Kexi, Geng Zhongming, and Kong Youde",
"question": "Who were the three Liandong Han bannermen who were instrumental in the taking of southern China?"
},
{
"answer": "southern China",
"question": "What part of China did Kexi, Zhongming, and Youde rule?"
},
{
"answer": "... |
17,843 | First, the Manchus had entered "China proper" because Dorgon responded decisively to Wu Sangui's appeal. Then, after capturing Beijing, instead of sacking the city as the rebels had done, Dorgon insisted, over the protests of other Manchu princes, on making it the dynastic capital and reappointing most Ming officials. ... | [
{
"answer": "Dorgon",
"question": "Who made Beijing his capital?"
},
{
"answer": "Ming",
"question": "Whose capital was Beijing before the Manchu's?"
},
{
"answer": "stabilize the regime and sped up the conquest of the rest of the country",
"question": "Why did Dorgon keep Beijing as... |
17,845 | Although his support had been essential to Shunzhi's ascent, Dorgon had through the years centralised so much power in his hands as to become a direct threat to the throne. So much so that upon his death he was extraordinarily bestowed the posthumous title of Emperor Yi (Chinese: 義皇帝), the only instance in Qing history... | [
{
"answer": "Dorgon",
"question": "Who was a threat to Shunzhi's throne?"
},
{
"answer": "Emperor Yi",
"question": "What was Dorgon known as after death?"
},
{
"answer": "1661",
"question": "When did Shunzhi's death?"
},
{
"answer": "Hooge",
"question": "Who was Shunzhi's... |
17,846 | The Manchus sent Han Bannermen to fight against Koxinga's Ming loyalists in Fujian. The Qing carried out a massive depopulation policy and seaban forcing people to evacuated the coast in order to deprive Koxinga's Ming loyalists of resources, this has led to a myth that it was because Manchus were "afraid of water". In... | [
{
"answer": "Han Bannermen",
"question": "Who did the Manchus send to battle Koxinga's troops?"
},
{
"answer": "Fujian",
"question": "Where did the fight between Ming loyalists and Manchus occur?"
},
{
"answer": "water",
"question": "What were the Manchus accused of being afraid of?"... |
17,849 | Yet controlling the "Mandate of Heaven" was a daunting task. The vastness of China's territory meant that there were only enough banner troops to garrison key cities forming the backbone of a defense network that relied heavily on surrendered Ming soldiers. In addition, three surrendered Ming generals were singled out ... | [
{
"answer": "Wu Sangui",
"question": "Who was the most important Ming general?"
},
{
"answer": "Yunnan and Guizhou",
"question": "What provinces did Sangui control?"
},
{
"answer": "Shang Kexi and Geng Jingzhong",
"question": "Name the other two important Ming generals?"
},
{
... |
17,850 | As the years went by, the three feudal lords and their extensive territories became increasingly autonomous. Finally, in 1673, Shang Kexi petitioned Kangxi for permission to retire to his hometown in Liaodong province and nominated his son as his successor. The young emperor granted his retirement, but denied the hered... | [
{
"answer": "1673",
"question": "When did Kexi retire?"
},
{
"answer": "his son",
"question": "Who did Kexi thing should take over for him?"
},
{
"answer": "all three fiefdoms to be reverted to the crown.",
"question": "What happened when Kexi, and the two other generals all retired?... |
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