Symbiosis

context: Symbiosis (from Greek σύν "together" and βίωσις "living") is close and often long-term interaction between two different biological species. In 1877 Albert Bernhard Frank used the word symbiosis (which previously had been used to depict people living together in community) to describe the mutualistic relationship in lichens. In 1879, the German mycologist Heinrich Anton de Bary defined it as "the living together of unlike organisms."
qas: answers: text: Greek
question: What language does the word "symbiosis" come from?

answers: text: lichens
question: What type of organism did Frank apply the term "symbiosis" to?

answers: text: German
question: What nationality was Heinrich Anton de Bary?

context: The definition of symbiosis has varied among scientists. Some believe symbiosis should only refer to persistent mutualisms, while others believe it should apply to any type of persistent biological interaction (in other words mutualistic, commensalistic, or parasitic). After 130 years of debate, current biology and ecology textbooks now use the latter "de Bary" definition or an even broader definition (where symbiosis means all species interactions), with the restrictive definition no longer used (in other words, symbiosis means mutualism).
qas: answers: text: 130 years
question: How long did it take for scientists to stop using the narrow definition of symbiosis?

context: Some symbiotic relationships are obligate, meaning that both symbionts entirely depend on each other for survival. For example, many lichens consist of fungal and photosynthetic symbionts that cannot live on their own. Others are facultative (optional): they can, but do not have to live with the other organism.
qas: answers: text: obligate
question: What is the type of symbiotic relationship where two organisms can't survive without each other?

answers: text: facultative
question: What is the type of symbiotic relationship where the symbionts can live together but can also survive alone?

answers: text: lichens
question: What is an example of an obligate relationship?

context: Symbiotic relationships include those associations in which one organism lives on another (ectosymbiosis, such as mistletoe), or where one partner lives inside the other (endosymbiosis, such as lactobacilli and other bacteria in humans or Symbiodinium in corals). Symbiosis is also classified by physical attachment of the organisms; symbiosis in which the organisms have bodily union is called conjunctive symbiosis, and symbiosis in which they are not in union is called disjunctive symbiosis.
qas: answers: text: mistletoe
question: What is an example of ectosymbiosis?

answers: text: disjunctive symbiosis
question: What is it called when the organisms are not physically joined?

answers: text: endosymbiosis
question: What is it called when one symbiont lives within its partner?

context: Endosymbiosis is any symbiotic relationship in which one symbiont lives within the tissues of the other, either within the cells or extracellularly. Examples include diverse microbiomes, rhizobia, nitrogen-fixing bacteria that live in root nodules on legume roots; actinomycete nitrogen-fixing bacteria called Frankia, which live in alder tree root nodules; single-celled algae inside reef-building corals; and bacterial endosymbionts that provide essential nutrients to about 10%–15% of insects.
qas: answers: text: insects
question: What do bacterial endosymbionts give necessary nutrition to?

answers: text: Frankia
question: What is the name of a bacteria inside of tree roots?

answers: text: algae
question: What endosymbionts live in coral? 

context: Ectosymbiosis, also referred to as exosymbiosis, is any symbiotic relationship in which the symbiont lives on the body surface of the host, including the inner surface of the digestive tract or the ducts of exocrine glands. Examples of this include ectoparasites such as lice, commensal ectosymbionts such as the barnacles that attach themselves to the jaw of baleen whales, and mutualist ectosymbionts such as cleaner fish.
qas: answers: text: barnacles
question: What organisms are described as living on the surface of whales?

answers: text: lice
question: Name a parasitic ectosymbiont.

answers: text: exosymbiosis
question: What is another name for ectosymbiosis?

context: Mutualism or interspecies reciprocal altruism is a relationship between individuals of different species where both individuals benefit. In general, only lifelong interactions involving close physical and biochemical contact can properly be considered symbiotic. Mutualistic relationships may be either obligate for both species, obligate for one but facultative for the other, or facultative for both. Many biologists restrict the definition of symbiosis to close mutualist relationships.
qas: answers: text: interspecies reciprocal altruism
question: What is another term for mutualism?

answers: text: lifelong
question: Of what duration are symbiotic relationships?

context: A large percentage of herbivores have mutualistic gut flora that help them digest plant matter, which is more difficult to digest than animal prey. This gut flora is made up of cellulose-digesting protozoans or bacteria living in the herbivores' intestines. Coral reefs are the result of mutualisms between coral organisms and various types of algae that live inside them. Most land plants and land ecosystems rely on mutualisms between the plants, which fix carbon from the air, and mycorrhyzal fungi, which help in extracting water and minerals from the ground.
qas: answers: text: mutualistic
question: What type of relationship do herbivores have with the bacteria in their intestines?

answers: text: Coral reefs
question: What do coral and algae produce together?

answers: text: fix carbon from the air
question: How do plants contribute to terrestrial ecosystems?

answers: text: mycorrhyzal
question: What type of fungus draws liquid and minerals out of the earth?

context: An example of mutual symbiosis is the relationship between the ocellaris clownfish that dwell among the tentacles of Ritteri sea anemones. The territorial fish protects the anemone from anemone-eating fish, and in turn the stinging tentacles of the anemone protect the clownfish from its predators. A special mucus on the clownfish protects it from the stinging tentacles.
qas: answers: text: ocellaris clownfish
question: What lives with Ritteri sea anemones?

answers: text: A special mucus
question: What prevents the clownfish from being stung?

answers: text: mutual symbiosis
question: What type of relationship do the clownfish and anemone have?

context: A further example is the goby fish, which sometimes lives together with a shrimp. The shrimp digs and cleans up a burrow in the sand in which both the shrimp and the goby fish live. The shrimp is almost blind, leaving it vulnerable to predators when outside its burrow. In case of danger the goby fish touches the shrimp with its tail to warn it. When that happens both the shrimp and goby fish quickly retreat into the burrow. Different species of gobies (Elacatinus spp.) also exhibit mutualistic behavior through cleaning up ectoparasites in other fish.
qas: answers: text: the goby fish
question: What species does this shrimp have a relationship with?

answers: text: its tail
question: What part of the fish is used to signal danger?

context: Another non-obligate symbiosis is known from encrusting bryozoans and hermit crabs that live in a close relationship. The bryozoan colony (Acanthodesia commensale) develops a cirumrotatory growth and offers the crab (Pseudopagurus granulimanus) a helicospiral-tubular extension of its living chamber that initially was situated within a gastropod shell.
qas: answers: text: non-obligate
question: What type of symbiosis seen between bryozoans and hermit crabs?

context: One of the most spectacular examples of obligate mutualism is between the siboglinid tube worms and symbiotic bacteria that live at hydrothermal vents and cold seeps. The worm has no digestive tract and is wholly reliant on its internal symbionts for nutrition. The bacteria oxidize either hydrogen sulfide or methane, which the host supplies to them. These worms were discovered in the late 1980s at the hydrothermal vents near the Galapagos Islands and have since been found at deep-sea hydrothermal vents and cold seeps in all of the world's oceans.
qas: answers: text: the late 1980s
question: When were the worms found?

answers: text: nutrition
question: What does the bacteria give the worm?

answers: text: the Galapagos Islands
question: What land is near the worms' first known location?

context: During mutualistic symbioses, the host cell lacks some of the nutrients, which are provided by the endosymbiont. As a result, the host favors endosymbiont's growth processes within itself by producing some specialized cells. These cells affect the genetic composition of the host in order to regulate the increasing population of the endosymbionts and ensuring that these genetic changes are passed onto the offspring via vertical transmission (heredity).
qas: answers: text: nutrients
question: What is given to the host cell?

answers: text: specialized cells
question: What does the host make that affect its genes?

answers: text: vertical transmission
question: In what manner are the described genetic alternations given to future generations?

context: Adaptation of the endosymbiont to the host's lifestyle leads to many changes in the endosymbiont–the foremost being drastic reduction in its genome size. This is due to many genes being lost during the process of metabolism, and DNA repair and recombination. While important genes participating in the DNA to RNA transcription, protein translation and DNA/RNA replication are retained. That is, a decrease in genome size is due to loss of protein coding genes and not due to lessening of inter-genic regions or open reading frame (ORF) size. Thus, species that are naturally evolving and contain reduced sizes of genes can be accounted for an increased number of noticeable differences between them, thereby leading to changes in their evolutionary rates. As the endosymbiotic bacteria related with these insects are passed on to the offspring strictly via vertical genetic transmission, intracellular bacteria goes through many hurdles during the process, resulting in the decrease in effective population sizes when compared to the free living bacteria. This incapability of the endosymbiotic bacteria to reinstate its wild type phenotype via a recombination process is called as Muller's ratchet phenomenon. Muller's ratchet phenomenon together with less effective population sizes has led to an accretion of deleterious mutations in the non-essential genes of the intracellular bacteria. This could have been due to lack of selection mechanisms prevailing in the rich environment of the host.
qas: answers: text: drastic reduction in its genome size
question: What is the main alteration in an endosymbiont when it adapts to a host?

answers: text: Muller's ratchet phenomenon
question: What is the term that describes the way the endosymbiont can't go back to its original phenotype?

answers: text: lack of selection mechanisms
question: What does the article say could be the reason for the buildup of harmful mutations?

context: Commensalism describes a relationship between two living organisms where one benefits and the other is not significantly harmed or helped. It is derived from the English word commensal used of human social interaction. The word derives from the medieval Latin word, formed from com- and mensa, meaning "sharing a table".
qas: answers: text: Latin
question: What language do the roots of "commensal" come from?

answers: text: Commensalism
question: What type of symbiotic relationship helps one organism and doesn't have a major affect on the other?

context: Commensal relationships may involve one organism using another for transportation (phoresy) or for housing (inquilinism), or it may also involve one organism using something another created, after its death (metabiosis). Examples of metabiosis are hermit crabs using gastropod shells to protect their bodies and spiders building their webs on plants.
qas: answers: text: inquilinism
question: What is the term for a relationship where one organism provides a dwelling for the other?

answers: text: metabiosis
question: What type of relationship is it when arachnids attach webs to dead plants?

answers: text: phoresy
question: In what type of relationship does an organism travel by means of another?

context: A parasitic relationship is one in which one member of the association benefits while the other is harmed. This is also known as antagonistic or antipathetic symbiosis. Parasitic symbioses take many forms, from endoparasites that live within the host's body to ectoparasites that live on its surface. In addition, parasites may be necrotrophic, which is to say they kill their host, or biotrophic, meaning they rely on their host's surviving. Biotrophic parasitism is an extremely successful mode of life. Depending on the definition used, as many as half of all animals have at least one parasitic phase in their life cycles, and it is also frequent in plants and fungi. Moreover, almost all free-living animals are host to one or more parasite taxa. An example of a biotrophic relationship would be a tick feeding on the blood of its host.
qas: answers: text: A parasitic relationship
question: Antagonistic or antipathetic symbiosis are alternate names for what?

answers: text: necrotrophic
question: What is it called when organisms are lethal to their host?

answers: text: biotrophic
question: What is it called when parasites need their host to live?

answers: text: as many as half
question: What proportion of animals go through a parasitic stage?

answers: text: a tick
question: Name a biotrophic organism.

context: Amensalism is the type of relationship that exists where one species is inhibited or completely obliterated and one is unaffected. This type of symbiosis is relatively uncommon in rudimentary reference texts, but is omnipresent in the natural world.[citation needed] There are two types of amensalism, competition and antibiosis. Competition is where a larger or stronger organisms deprives a smaller or weaker one from a resource. Antibiosis occurs when one organism is damaged or killed by another through a chemical secretion. An example of competition is a sapling growing under the shadow of a mature tree. The mature tree can begin to rob the sapling of necessary sunlight and, if the mature tree is very large, it can take up rainwater and deplete soil nutrients. Throughout the process the mature tree is unaffected. Indeed, if the sapling dies, the mature tree gains nutrients from the decaying sapling. Note that these nutrients become available because of the sapling's decomposition, rather than from the living sapling, which would be a case of parasitism.[citation needed] An example of antibiosis is Juglans nigra (black walnut), secreting juglone, a substance which destroys many herbaceous plants within its root zone.
qas: answers: text: Amensalism
question: What is the name for the kind of symbiosis in which one organism is seriously harmed and there is no affect on the other?

answers: text: competition and antibiosis
question: What kinds of amensalism are there?

answers: text: competition
question: When a large tree takes the resources a young tree needs, what type of amensalism is it?

answers: text: juglone
question: What does the black walnut give out that kills plants?

context: Amensalism is an interaction where an organism inflicts harm to another organism without any costs or benefits received by the other. A clear case of amensalism is where sheep or cattle trample grass. Whilst the presence of the grass causes negligible detrimental effects to the animal's hoof, the grass suffers from being crushed. Amensalism is often used to describe strongly asymmetrical competitive interactions, such as has been observed between the Spanish ibex and weevils of the genus Timarcha which feed upon the same type of shrub. Whilst the presence of the weevil has almost no influence on food availability, the presence of ibex has an enormous detrimental effect on weevil numbers, as they consume significant quantities of plant matter and incidentally ingest the weevils upon it.
qas: answers: text: weevils
question: What organisms is the ibex in an amensalistic relationship with?

answers: text: shrub
question: What does the Spanish ibex eat?

answers: text: Amensalism
question: What type of relationship is it when large animals crush small plants?

context: Synnecrosis is a rare type of symbiosis in which the interaction between species is detrimental to both organisms involved. It is a short-lived condition, as the interaction eventually causes death. Because of this, evolution selects against synnecrosis and it is uncommon in nature. An example of this is the relationship between some species of bees and victims of the bee sting. Species of bees who die after stinging their prey inflict pain on themselves (albeit to protect the hive) as well as on the victim. This term is rarely used.
qas: answers: text: Synnecrosis
question: What type of relationship harms both organisms?

answers: text: death
question: What is the ultimate result of synnecrosis?

answers: text: uncommon
question: How common is synnecrosis in the natural world?

answers: text: to protect the hive
question: Why do bees sting even though it will kill them?

context: While historically, symbiosis has received less attention than other interactions such as predation or competition, it is increasingly recognized as an important selective force behind evolution, with many species having a long history of interdependent co-evolution. In fact, the evolution of all eukaryotes (plants, animals, fungi, and protists) is believed under the endosymbiotic theory to have resulted from a symbiosis between various sorts of bacteria. This theory is supported by certain organelles dividing independently of the cell, and the observation that some organelles seem to have their own nucleic acid.
qas: answers: text: the evolution of all eukaryotes
question: What far-reaching result do scientists think has come about from symbiosis with bacteria?

answers: text: plants, animals, fungi, and protists
question: What are eukaryotes?

context: The biologist Lynn Margulis, famous for her work on endosymbiosis, contends that symbiosis is a major driving force behind evolution. She considers Darwin's notion of evolution, driven by competition, to be incomplete and claims that evolution is strongly based on co-operation, interaction, and mutual dependence among organisms. According to Margulis and Dorion Sagan, "Life did not take over the globe by combat, but by networking."
qas: answers: text: symbiosis
question: What does Margulis think is the main driver of evolution?

answers: text: Dorion Sagan
question: Who agrees with Margulis' cooperative view of evolution?

context: Symbiosis played a major role in the co-evolution of flowering plants and the animals that pollinate them. Many plants that are pollinated by insects, bats, or birds have highly specialized flowers modified to promote pollination by a specific pollinator that is also correspondingly adapted. The first flowering plants in the fossil record had relatively simple flowers. Adaptive speciation quickly gave rise to many diverse groups of plants, and, at the same time, corresponding speciation occurred in certain insect groups. Some groups of plants developed nectar and large sticky pollen, while insects evolved more specialized morphologies to access and collect these rich food sources. In some taxa of plants and insects the relationship has become dependent, where the plant species can only be pollinated by one species of insect.
qas: answers: text: a major role
question: How big a part did symbiosis have in the development of flowering plants and their pollinators?

answers: text: nectar and large sticky pollen
question: What did some plants produce when flowers became less simple?

answers: text: dependent
question: What is the word for the kind of relationship in which a plant depend on a single type of insect?