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65-756: The range stretches from the Lusatian Mountains ( Zittau Mountains ) in the northwest to the Krkonoše in the southeast. The Jizera Mountains comprise the sources of the Jizera river, as well as of the Kwisa and the Lusatian Neisse . The major part in the south is formed from granite , in the northern part from gneisses and mica schists , with some areas formed from basalt . The weather conditions are characterized by above-average annual precipitation . On 30 July 1897,

130-438: A holoparasite such as Cuscuta derives all of its nutrients from another plant. Parasitic plants make up about one per cent of angiosperms and are in almost every biome in the world. All these plants have modified roots, haustoria , which penetrate the host plants, connecting them to the conductive system—either the xylem , the phloem , or both. This provides them with the ability to extract water and nutrients from

195-511: A cause of gastroenteritis , is spread by the fecal–oral route from animals, or by eating insufficiently cooked poultry , or by contaminated water. Haemophilus influenzae , an agent of bacterial meningitis and respiratory tract infections such as influenza and bronchitis , is transmitted by droplet contact. Treponema pallidum , the cause of syphilis , is spread by sexual activity . Viruses are obligate intracellular parasites, characterised by extremely limited biological function, to

260-627: A faster rate than their hosts. Classic examples include interactions between vertebrate hosts and tapeworms , flukes , and those between the malaria-causing Plasmodium species, and fleas . Parasites reduce host fitness by general or specialised pathology , that ranges from parasitic castration to modification of host behaviour . Parasites increase their own fitness by exploiting hosts for resources necessary for their survival, in particular by feeding on them and by using intermediate (secondary) hosts to assist in their transmission from one definitive (primary) host to another. Although parasitism

325-595: A hormone or by diverting nutrients. For example, the trematode Zoogonus lasius , whose sporocysts lack mouths, castrates the intertidal marine snail Tritia obsoleta chemically, developing in its gonad and killing its reproductive cells. Directly transmitted parasites, not requiring a vector to reach their hosts, include such parasites of terrestrial vertebrates as lice and mites; marine parasites such as copepods and cyamid amphipods; monogeneans ; and many species of nematodes, fungi, protozoans, bacteria, and viruses. Whether endoparasites or ectoparasites, each has

390-836: A parasite employs to identify and approach a potential host are known as "host cues". Such cues can include, for example, vibration, exhaled carbon dioxide , skin odours, visual and heat signatures, and moisture. Parasitic plants can use, for example, light, host physiochemistry, and volatiles to recognize potential hosts. There are six major parasitic strategies , namely parasitic castration ; directly transmitted parasitism; trophically -transmitted parasitism; vector -transmitted parasitism; parasitoidism ; and micropredation. These apply to parasites whose hosts are plants as well as animals. These strategies represent adaptive peaks ; intermediate strategies are possible, but organisms in many different groups have consistently converged on these six, which are evolutionarily stable. A perspective on

455-618: A parasitic alien species. First used in English in 1539, the word parasite comes from the Medieval French parasite , from the Latinised form parasitus , from Ancient Greek παράσιτος (parasitos)  'one who eats at the table of another' in turn from παρά (para)  'beside, by' and σῖτος (sitos)  'wheat, food'. The related term parasitism appears in English from 1611. Parasitism

520-432: A phenomenon termed the biotrophy-necrotrophy switch . Pathogenic fungi are well-known causative agents of diseases on animals as well as humans. Fungal infections ( mycosis ) are estimated to kill 1.6 million people each year. One example of a potent fungal animal pathogen are Microsporidia - obligate intracellular parasitic fungi that largely affect insects, but may also affect vertebrates including humans, causing

585-533: A predator, the European sparrowhawk , giving her time to lay her eggs in the host's nest unobserved. Host species often combat parasitic egg mimicry through egg polymorphism , having two or more egg phenotypes within a single population of a species. Multiple phenotypes in host eggs decrease the probability of a parasitic species accurately "matching" their eggs to host eggs. In kleptoparasitism (from Greek κλέπτης ( kleptēs ), "thief"), parasites steal food gathered by

650-573: A single host-species. Within that species, most individuals are free or almost free of parasites, while a minority carry a large number of parasites; this is known as an aggregated distribution . Trophically -transmitted parasites are transmitted by being eaten by a host. They include trematodes (all except schistosomes ), cestodes , acanthocephalans , pentastomids , many roundworms , and many protozoa such as Toxoplasma . They have complex life cycles involving hosts of two or more species. In their juvenile stages they infect and often encyst in

715-430: A suitable fungus soon after germinating. Parasitic fungi derive some or all of their nutritional requirements from plants, other fungi, or animals. Plant pathogenic fungi are classified into three categories depending on their mode of nutrition: biotrophs, hemibiotrophs and necrotrophs. Biotrophic fungi derive nutrients from living plant cells, and during the course of infection they colonise their plant host in such

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780-1047: A variety of methods to infect animal hosts, including physical contact, the fecal–oral route , free-living infectious stages, and vectors, suiting their differing hosts, life cycles, and ecological contexts. Examples to illustrate some of the many possible combinations are given in the table. social behaviour (grooming) Among the many variations on parasitic strategies are hyperparasitism, social parasitism, brood parasitism, kleptoparasitism, sexual parasitism, and adelphoparasitism. Hyperparasites feed on another parasite, as exemplified by protozoa living in helminth parasites, or facultative or obligate parasitoids whose hosts are either conventional parasites or parasitoids. Levels of parasitism beyond secondary also occur, especially among facultative parasitoids. In oak gall systems, there can be up to five levels of parasitism. Hyperparasites can control their hosts' populations, and are used for this purpose in agriculture and to some extent in medicine . The controlling effects can be seen in

845-469: A variety of routes. To give a few examples, Bacillus anthracis , the cause of anthrax , is spread by contact with infected domestic animals ; its spores , which can survive for years outside the body, can enter a host through an abrasion or may be inhaled. Borrelia , the cause of Lyme disease and relapsing fever , is transmitted by vectors, ticks of the genus Ixodes , from the diseases' reservoirs in animals such as deer . Campylobacter jejuni ,

910-474: A way as to keep it alive for a maximally long time. One well-known example of a biotrophic pathogen is Ustilago maydis , causative agent of the corn smut disease. Necrotrophic pathogens on the other hand, kill host cells and feed saprophytically , an example being the root-colonising honey fungi in the genus Armillaria . Hemibiotrophic pathogens begin their colonising their hosts as biotrophs, and subsequently killing off host cells and feeding as necrotrophs,

975-569: Is Bedřichov . The international cross-country races Jizerská 50 and Bieg Piastów (in Polana Jakuszycka ) take place there. Its summer MTB counterpart is also gaining popularity. The towns surrounding the mountains include Liberec , Frýdlant v Čechách , Nové Město pod Smrkem , Świeradów Zdrój , Szklarska Poręba , Desná, Tanvald and Jablonec nad Nisou . Large parts of the Jizera Mountains are under some form of protection. In

1040-563: Is a kind of symbiosis , a close and persistent long-term biological interaction between a parasite and its host. Unlike saprotrophs , parasites feed on living hosts, though some parasitic fungi, for instance, may continue to feed on hosts they have killed. Unlike commensalism and mutualism , the parasitic relationship harms the host, either feeding on it or, as in the case of intestinal parasites, consuming some of its food. Because parasites interact with other species, they can readily act as vectors of pathogens, causing disease . Predation

1105-675: Is aggregated. Coinfection by multiple parasites is common. Autoinfection , where (by exception) the whole of the parasite's life cycle takes place in a single primary host, can sometimes occur in helminths such as Strongyloides stercoralis . Vector-transmitted parasites rely on a third party, an intermediate host, where the parasite does not reproduce sexually, to carry them from one definitive host to another. These parasites are microorganisms, namely protozoa , bacteria , or viruses , often intracellular pathogens (disease-causers). Their vectors are mostly hematophagic arthropods such as fleas, lice, ticks, and mosquitoes. For example,

1170-443: Is by definition not a symbiosis, as the interaction is brief, but the entomologist E. O. Wilson has characterised parasites as "predators that eat prey in units of less than one". Within that scope are many possible strategies. Taxonomists classify parasites in a variety of overlapping schemes, based on their interactions with their hosts and on their life cycles , which can be complex. An obligate parasite depends completely on

1235-645: Is found in the ant Tetramorium inquilinum , an obligate parasite which lives exclusively on the backs of other Tetramorium ants. A mechanism for the evolution of social parasitism was first proposed by Carlo Emery in 1909. Now known as " Emery's rule ", it states that social parasites tend to be closely related to their hosts, often being in the same genus. Intraspecific social parasitism occurs in parasitic nursing, where some individual young take milk from unrelated females. In wedge-capped capuchins , higher ranking females sometimes take milk from low ranking females without any reciprocation. In brood parasitism ,

1300-585: Is often unambiguous, it is part of a spectrum of interactions between species , grading via parasitoidism into predation, through evolution into mutualism , and in some fungi, shading into being saprophytic . Human knowledge of parasites such as roundworms and tapeworms dates back to ancient Egypt , Greece , and Rome . In early modern times, Antonie van Leeuwenhoek observed Giardia lamblia with his microscope in 1681, while Francesco Redi described internal and external parasites including sheep liver fluke and ticks . Modern parasitology developed in

1365-419: Is seen in some species of anglerfish , such as Ceratias holboelli , where the males are reduced to tiny sexual parasites , wholly dependent on females of their own species for survival, permanently attached below the female's body, and unable to fend for themselves. The female nourishes the male and protects him from predators, while the male gives nothing back except the sperm that the female needs to produce

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1430-469: Is then carried to a nest, sometimes alongside other prey if it is not large enough to support a parasitoid throughout its development. An egg is laid on top of the prey and the nest is then sealed. The parasitoid develops rapidly through its larval and pupal stages, feeding on the provisions left for it. Koinobiont parasitoids, which include flies as well as wasps, lay their eggs inside young hosts, usually larvae. These are allowed to go on growing, so

1495-673: The Elbe valley. The mountains of the northern, German, part are called the Zittau Mountains . The range is among the westernmost extensions of the Sudetes , which stretch along the border between the historic region of Silesia in the north, and Bohemia and Moravia in the south up to the Moravian Gate in the east, where they join the Carpathian Mountains . The northwestern foothills of

1560-550: The Tertiary volcanic magma streams broke through the sandstone layer and solidified into basalt and phonolite . Several sandstone contact areas were also hardened to columns and distinct rock formations. The highest peak is the Lausche (793 m). Other notable peaks include the Pěnkavčí vrch (792m), Jedlová (774m), Klíč (760m), Hochwald (750m) and Studenec (736m). The Czech part of

1625-505: The snubnosed eel is probably a facultative endoparasite (i.e., it is semiparasitic) that opportunistically burrows into and eats sick and dying fish. Plant-eating insects such as scale insects , aphids , and caterpillars closely resemble ectoparasites, attacking much larger plants; they serve as vectors of bacteria, fungi and viruses which cause plant diseases . As female scale insects cannot move, they are obligate parasites, permanently attached to their hosts. The sensory inputs that

1690-504: The 19th century. In human culture, parasitism has negative connotations. These were exploited to satirical effect in Jonathan Swift 's 1733 poem "On Poetry: A Rhapsody", comparing poets to hyperparasitical "vermin". In fiction, Bram Stoker 's 1897 Gothic horror novel Dracula and its many later adaptations featured a blood-drinking parasite. Ridley Scott 's 1979 film Alien was one of many works of science fiction to feature

1755-629: The Counts of Schaffgotsch from Schreiberhau ( Szklarska Poręba ), Lower Silesia . Following the defeat of Nazi Germany in World War II , in 1945, the northern part of the Jizera Mountains became again part of Poland, and the southern was restored to Czechoslovakia . The German population of the area was expelled in accordance with the Potsdam Agreement and replaced by Poles on the Polish and Czechs on

1820-575: The Czechoslovakian side of the mountains. The ecosystem was badly hit by emissions, produced by lignite fired power stations located in the Zittau basin, part of Europe's ecological Black Triangle . Weakened spruce forest, less resistant against various types of parasites , were on the verge of extinction. The higher parts of the mountains, once densely wooded, became largely treeless, in part also because of excessive deforestation. New roads cut through

1885-619: The Lightsome of the Piast dynasty granted a portion of the Izera Mountains to the Knights Hospitaller from Strzegom . In the 14th century, German-speaking colonists came and started clearing of the dense primeval forests . Permanent settlements were established. In the 16th century, several glass works were founded. Glassmaking had a profound effect on the ecosystem . The primeval forest

1950-685: The Lusatian Mountains are called the Lusatian Highlands ; in the southwest the range borders on the České Středohoří mountains. The range is largely made up of sandstone sedimentary rocks leaning on a Precambrian crystalline basement . The northern ridge is marked by the Lusatian Fault , a geological disturbance zone separating the Bohemian sandstones from the Lusatian granodiorite . During

2015-555: The Lusatian Mountains have been a nature reserve since 1976, covering an area of 264 km (102 sq mi). Administratively it is known as the Lusatian Mountains Protected Landscape Area ( CHKO Lužické hory ) and has the status of CHKO, a so-called Landscape park . The smaller German part of the mountains also became a nature protection in 2008, when the Zittau Mountain Nature Park

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2080-635: The agents of malaria , sleeping sickness , and amoebic dysentery ; animals such as hookworms , lice , mosquitoes , and vampire bats ; fungi such as honey fungus and the agents of ringworm ; and plants such as mistletoe , dodder , and the broomrapes . There are six major parasitic strategies of exploitation of animal hosts, namely parasitic castration , directly transmitted parasitism (by contact), trophically-transmitted parasitism (by being eaten), vector-transmitted parasitism, parasitoidism , and micropredation. One major axis of classification concerns invasiveness: an endoparasite lives inside

2145-696: The air or soil given off by host shoots or roots , respectively. About 4,500 species of parasitic plant in approximately 20 families of flowering plants are known. Species within the Orobanchaceae (broomrapes) are among the most economically destructive of all plants. Species of Striga (witchweeds) are estimated to cost billions of dollars a year in crop yield loss, infesting over 50 million hectares of cultivated land within Sub-Saharan Africa alone. Striga infects both grasses and grains, including corn , rice , and sorghum , which are among

2210-437: The area date back to prehistory . Later on, Celts , German tribes resides in the valleys until they left in 5th century. Later came Slavs . Since the 10th century, the border between Poland and Bohemia (Czechia) ran through the mountains. Following the fragmentation of Poland into smaller duchies, the Polish portion of the mountains was located in the duchies of Silesia , Legnica , Jawor and Lwówek . In 1281, Duke Bernard

2275-864: The deer tick Ixodes scapularis acts as a vector for diseases including Lyme disease , babesiosis , and anaplasmosis . Protozoan endoparasites, such as the malarial parasites in the genus Plasmodium and sleeping-sickness parasites in the genus Trypanosoma , have infective stages in the host's blood which are transported to new hosts by biting insects. Parasitoids are insects which sooner or later kill their hosts, placing their relationship close to predation. Most parasitoids are parasitoid wasps or other hymenopterans ; others include dipterans such as phorid flies . They can be divided into two groups, idiobionts and koinobionts, differing in their treatment of their hosts. Idiobiont parasitoids sting their often-large prey on capture, either killing them outright or paralysing them immediately. The immobilised prey

2340-409: The energy that would have gone into reproduction into host and parasite growth, sometimes causing gigantism in the host. The host's other systems remain intact, allowing it to survive and to sustain the parasite. Parasitic crustaceans such as those in the specialised barnacle genus Sacculina specifically cause damage to the gonads of their many species of host crabs . In the case of Sacculina ,

2405-491: The evolutionary options can be gained by considering four key questions: the effect on the fitness of a parasite's hosts; the number of hosts they have per life stage; whether the host is prevented from reproducing; and whether the effect depends on intensity (number of parasites per host). From this analysis, the major evolutionary strategies of parasitism emerge, alongside predation. Parasitic castrators partly or completely destroy their host's ability to reproduce, diverting

2470-444: The family Cuculidae , over 40% of cuckoo species are obligate brood parasites, while others are either facultative brood parasites or provide parental care. The eggs of some brood parasites mimic those of their hosts, while some cowbird eggs have tough shells, making them hard for the hosts to kill by piercing, both mechanisms implying selection by the hosts against parasitic eggs. The adult female European cuckoo further mimics

2535-424: The host and parasitoid develop together for an extended period, ending when the parasitoids emerge as adults, leaving the prey dead, eaten from inside. Some koinobionts regulate their host's development, for example preventing it from pupating or making it moult whenever the parasitoid is ready to moult. They may do this by producing hormones that mimic the host's moulting hormones ( ecdysteroids ), or by regulating

2600-442: The host to complete its life cycle, while a facultative parasite does not. Parasite life cycles involving only one host are called "direct"; those with a definitive host (where the parasite reproduces sexually) and at least one intermediate host are called "indirect". An endoparasite lives inside the host's body; an ectoparasite lives outside, on the host's surface. Mesoparasites—like some copepods , for example—enter an opening in

2665-422: The host's body and remain partly embedded there. Some parasites can be generalists, feeding on a wide range of hosts, but many parasites, and the majority of protozoans and helminths that parasitise animals, are specialists and extremely host-specific. An early basic, functional division of parasites distinguished microparasites and macroparasites. These each had a mathematical model assigned in order to analyse

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2730-453: The host's body; an ectoparasite lives outside, on the host's surface. Like predation, parasitism is a type of consumer–resource interaction , but unlike predators , parasites, with the exception of parasitoids, are much smaller than their hosts, do not kill them, and often live in or on their hosts for an extended period. Parasites of animals are highly specialised , each parasite species living on one given animal species, and reproduce at

2795-656: The host's endocrine system. A micropredator attacks more than one host, reducing each host's fitness by at least a small amount, and is only in contact with any one host intermittently. This behavior makes micropredators suitable as vectors, as they can pass smaller parasites from one host to another. Most micropredators are hematophagic , feeding on blood. They include annelids such as leeches , crustaceans such as branchiurans and gnathiid isopods, various dipterans such as mosquitoes and tsetse flies , other arthropods such as fleas and ticks, vertebrates such as lampreys , and mammals such as vampire bats . Parasites use

2860-425: The host. A parasitic plant is classified depending on where it latches onto the host, either the stem or the root, and the amount of nutrients it requires. Since holoparasites have no chlorophyll and therefore cannot make food for themselves by photosynthesis , they are always obligate parasites, deriving all their food from their hosts. Some parasitic plants can locate their host plants by detecting chemicals in

2925-477: The host. The parasitism is often on close relatives, whether within the same species or between species in the same genus or family. For instance, the many lineages of cuckoo bees lay their eggs in the nest cells of other bees in the same family. Kleptoparasitism is uncommon generally but conspicuous in birds; some such as skuas are specialised in pirating food from other seabirds, relentlessly chasing them down until they disgorge their catch. A unique approach

2990-423: The hosts suffer increased parental investment and energy expenditure to feed parasitic young, which are commonly larger than host young. The growth rate of host nestlings is slowed, reducing the host's fitness. Brood parasites include birds in different families such as cowbirds , whydahs , cuckoos , and black-headed ducks . These do not build nests of their own, but leave their eggs in nests of other species . In

3055-472: The intermediate host. When the intermediate-host animal is eaten by a predator, the definitive host, the parasite survives the digestion process and matures into an adult; some live as intestinal parasites . Many trophically transmitted parasites modify the behaviour of their intermediate hosts, increasing their chances of being eaten by a predator. As with directly transmitted parasites, the distribution of trophically transmitted parasites among host individuals

3120-471: The intestinal infection microsporidiosis . Protozoa such as Plasmodium , Trypanosoma , and Entamoeba are endoparasitic. They cause serious diseases in vertebrates including humans—in these examples, malaria, sleeping sickness, and amoebic dysentery —and have complex life cycles. Many bacteria are parasitic, though they are more generally thought of as pathogens causing disease. Parasitic bacteria are extremely diverse, and infect their hosts by

3185-441: The large blue butterfly, Phengaris arion , its larvae employing ant mimicry to parasitise certain ants, Bombus bohemicus , a bumblebee which invades the hives of other bees and takes over reproduction while their young are raised by host workers, and Melipona scutellaris , a eusocial bee whose virgin queens escape killer workers and invade another colony without a queen. An extreme example of interspecific social parasitism

3250-567: The largest group is the parasitoid wasps in the Hymenoptera. The phyla and classes with the largest numbers of parasitic species are listed in the table. Numbers are conservative minimum estimates. The columns for Endo- and Ecto-parasitism refer to the definitive host, as documented in the Vertebrate and Invertebrate columns. A hemiparasite or partial parasite such as mistletoe derives some of its nutrients from another living plant, whereas

3315-537: The marine worm Bonellia viridis has a similar reproductive strategy, although the larvae are planktonic. Examples of the major variant strategies are illustrated. Parasitism has an extremely wide taxonomic range, including animals, plants, fungi, protozoans, bacteria, and viruses. Parasitism is widespread in the animal kingdom, and has evolved independently from free-living forms hundreds of times. Many types of helminth including flukes and cestodes have complete life cycles involving two or more hosts. By far

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3380-586: The measuring station at Nová Louka recorded a daily precipitation amounting to 345.1 mm (13.6 inches), still an unbroken European record. The highest peak is Wysoka Kopa (1,127 m, 3,698 feet) near the town of Szklarska Poręba in Poland. Neverteheless, a better-known mountain is Smrk (1124 m, 3,688 feet), with a recently rebuilt look-out tower. Other peaks include Jizera (1,122 m, 3,681 feet) and Stóg Izerski ( Heufuder , 1,107 m, 3,632). The peaks in order of elevation: The first settlements in

3445-407: The next generation. Adelphoparasitism, (from Greek ἀδελφός ( adelphós ), brother ), also known as sibling-parasitism, occurs where the host species is closely related to the parasite, often in the same family or genus. In the citrus blackfly parasitoid, Encarsia perplexa , unmated females may lay haploid eggs in the fully developed larvae of their own species, producing male offspring, while

3510-580: The once-secluded landscape. The situation improved only after the fall of communism in 1989. Open-pit coal mines in the former East Germany were closed, as well as several major power plants. Emission filters were installed at the immense Turów Power Station in Bogatynia on the Polish side of Lusatian Neisse . At the same time large-scale reforestation projects were started. The Jizera Mountains are an attractive location for winter sports, cycling and hiking. The centre for both downhill skiing and ski run

3575-417: The point where, while they are evidently able to infect all other organisms from bacteria and archaea to animals, plants and fungi, it is unclear whether they can themselves be described as living. They can be either RNA or DNA viruses consisting of a single or double strand of genetic material ( RNA or DNA , respectively), covered in a protein coat and sometimes a lipid envelope. They thus lack all

3640-535: The population movements of the host–parasite groupings. The microorganisms and viruses that can reproduce and complete their life cycle within the host are known as microparasites. Macroparasites are the multicellular organisms that reproduce and complete their life cycle outside of the host or on the host's body. Much of the thinking on types of parasitism has focused on terrestrial animal parasites of animals, such as helminths. Those in other environments and with other hosts often have analogous strategies. For example,

3705-694: The quarter Neugablonz of the Bavarian town Kaufbeuren is devoted to the German history of the region. Lusatian Mountains The Lusatian Mountains ( Czech : Lužické hory ; German : Lausitzer Gebirge ; Polish : Góry Łużyckie ) are a mountain range of the Western Sudetes on the southeastern border of Germany with the Czech Republic . They are a continuation of the Ore Mountains range west of

3770-639: The smaller Polish parts, the peat bogs in Jizera Valley are part of a relatively small nature protection of about 5 km; Rezerwat Torfowiska Doliny Izery. In the Czech parts, Jizera Mountains Protected Landscape Area ( CHKO Jizerské hory ) covers 368 km, or almost all of the Czech parts of the mountains. This landscape protection contains several reserves, including the Jizera Dark Sky Park ( Rašeliniště Jizery ), dedicated to star watching. A museum in

3835-466: The testes of over two-thirds of their crab hosts degenerate sufficiently for these male crabs to develop female secondary sex characteristics such as broader abdomens, smaller claws and egg-grasping appendages. Various species of helminth castrate their hosts (such as insects and snails). This may happen directly, whether mechanically by feeding on their gonads, or by secreting a chemical that destroys reproductive cells; or indirectly, whether by secreting

3900-403: The tropics, however effectively cheat by taking carbon from a fungus rather than exchanging it for minerals. They have much reduced roots, as they do not need to absorb water from the soil; their stems are slender with few vascular bundles , and their leaves are reduced to small scales, as they do not photosynthesize. Their seeds are small and numerous, so they appear to rely on being infected by

3965-506: The usual machinery of the cell such as enzymes , relying entirely on the host cell's ability to replicate DNA and synthesise proteins. Most viruses are bacteriophages , infecting bacteria. Parasitism is a major aspect of evolutionary ecology; for example, almost all free-living animals are host to at least one species of parasite. Vertebrates, the best-studied group, are hosts to between 75,000 and 300,000 species of helminths and an uncounted number of parasitic microorganisms. On average,

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4030-585: The way that the CHV1 virus helps to control the damage that chestnut blight , Cryphonectria parasitica , does to American chestnut trees, and in the way that bacteriophages can limit bacterial infections. It is likely, though little researched, that most pathogenic microparasites have hyperparasites which may prove widely useful in both agriculture and medicine. Social parasites take advantage of interspecific interactions between members of eusocial animals such as ants , termites , and bumblebees . Examples include

4095-471: The world's most important food crops. Orobanche also threatens a wide range of other important crops, including peas , chickpeas , tomatoes , carrots , and varieties of cabbage . Yield loss from Orobanche can be total; despite extensive research, no method of control has been entirely successful. Many plants and fungi exchange carbon and nutrients in mutualistic mycorrhizal relationships. Some 400 species of myco-heterotrophic plants, mostly in

4160-562: Was established, with the effect that the entire Lusatian Mountains is now under some form of nature protection. Parasitism This is an accepted version of this page Parasitism is a close relationship between species , where one organism, the parasite, lives on or inside another organism, the host , causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson characterised parasites as "predators that eat prey in units of less than one". Parasites include single-celled protozoans such as

4225-565: Was gradually replaced by fast-growing spruce monoculture. Other important industries included tin-mining, metallurgy and textile. The Tabulový kámen ( German : Tafelstein , 1072 m) on the northern edge of the Smrk Mountain marked the border between the properties of the Counts of Gallas  [ de ; cs ] in Friedland , Bohemia , the von Gersdorff family from Meffersdorf (Unięcice, now part of Pobiedna ), Upper Lusatia and

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