1.
Taxonomy (biology)
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Taxonomy is the science of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. The exact definition of taxonomy varies from source to source, but the core of the remains, the conception, naming. There is some disagreement as to whether biological nomenclature is considered a part of taxonomy, the broadest meaning of taxonomy is used here. The word taxonomy was introduced in 1813 by Candolle, in his Théorie élémentaire de la botanique, the term alpha taxonomy is primarily used today to refer to the discipline of finding, describing, and naming taxa, particularly species. In earlier literature, the term had a different meaning, referring to morphological taxonomy, ideals can, it may be said, never be completely realized. They have, however, a value of acting as permanent stimulants. Some of us please ourselves by thinking we are now groping in a beta taxonomy, turrill thus explicitly excludes from alpha taxonomy various areas of study that he includes within taxonomy as a whole, such as ecology, physiology, genetics, and cytology. He further excludes phylogenetic reconstruction from alpha taxonomy, thus, Ernst Mayr in 1968 defined beta taxonomy as the classification of ranks higher than species. This activity is what the term denotes, it is also referred to as beta taxonomy. How species should be defined in a group of organisms gives rise to practical and theoretical problems that are referred to as the species problem. The scientific work of deciding how to define species has been called microtaxonomy, by extension, macrotaxonomy is the study of groups at higher taxonomic ranks, from subgenus and above only, than species. While some descriptions of taxonomic history attempt to date taxonomy to ancient civilizations, earlier works were primarily descriptive, and focused on plants that were useful in agriculture or medicine. There are a number of stages in scientific thinking. Early taxonomy was based on criteria, the so-called artificial systems. Later came systems based on a complete consideration of the characteristics of taxa, referred to as natural systems, such as those of de Jussieu, de Candolle and Bentham. The publication of Charles Darwins Origin of Species led to new ways of thinking about classification based on evolutionary relationships and this was the concept of phyletic systems, from 1883 onwards. This approach was typified by those of Eichler and Engler, the advent of molecular genetics and statistical methodology allowed the creation of the modern era of phylogenetic systems based on cladistics, rather than morphology alone. Taxonomy has been called the worlds oldest profession, and naming and classifying our surroundings has likely been taking place as long as mankind has been able to communicate
2.
Animal
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Animals are multicellular, eukaryotic organisms of the kingdom Animalia. The animal kingdom emerged as a clade within Apoikozoa as the group to the choanoflagellates. Animals are motile, meaning they can move spontaneously and independently at some point in their lives and their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later in their lives. All animals are heterotrophs, they must ingest other organisms or their products for sustenance, most known animal phyla appeared in the fossil record as marine species during the Cambrian explosion, about 542 million years ago. Animals can be divided broadly into vertebrates and invertebrates, vertebrates have a backbone or spine, and amount to less than five percent of all described animal species. They include fish, amphibians, reptiles, birds and mammals, the remaining animals are the invertebrates, which lack a backbone. These include molluscs, arthropods, annelids, nematodes, flatworms, cnidarians, ctenophores, the study of animals is called zoology. The word animal comes from the Latin animalis, meaning having breath, the biological definition of the word refers to all members of the kingdom Animalia, encompassing creatures as diverse as sponges, jellyfish, insects, and humans. Aristotle divided the world between animals and plants, and this was followed by Carl Linnaeus, in the first hierarchical classification. In Linnaeuss original scheme, the animals were one of three kingdoms, divided into the classes of Vermes, Insecta, Pisces, Amphibia, Aves, and Mammalia. Since then the last four have all been subsumed into a single phylum, in 1874, Ernst Haeckel divided the animal kingdom into two subkingdoms, Metazoa and Protozoa. The protozoa were later moved to the kingdom Protista, leaving only the metazoa, thus Metazoa is now considered a synonym of Animalia. Animals have several characteristics that set apart from other living things. Animals are eukaryotic and multicellular, which separates them from bacteria and they are heterotrophic, generally digesting food in an internal chamber, which separates them from plants and algae. They are also distinguished from plants, algae, and fungi by lacking cell walls. All animals are motile, if only at life stages. In most animals, embryos pass through a stage, which is a characteristic exclusive to animals. With a few exceptions, most notably the sponges and Placozoa and these include muscles, which are able to contract and control locomotion, and nerve tissues, which send and process signals
3.
Phylum
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In biology, a phylum is a taxonomic rank below kingdom and above class. Traditionally, in botany the term division was used instead of phylum, although from 1993 the International Code of Nomenclature for algae, fungi, depending on definitions, the kingdom Animalia contains approximately 35 phyla, Plantae contains about 12, and Fungi contains around 7. Current research in phylogenetics is uncovering the relationships between phyla, which are contained in larger clades, like Ecdysozoa and Embryophyta, the definitions of zoological phyla have changed from their origins in the six Linnaean classes and the four embranchements of Georges Cuvier. Haeckel introduced the term phylum, based on the Greek word phylon, in plant taxonomy, Eichler classified plants into five groups, named divisions. Informally, phyla can be thought of as grouping organisms based on general specialization of body plan, the most important objective measure in the above definitions is the certain degree—how unrelated do organisms need to be to be members of different phyla. The minimal requirement is that all organisms in a phylum should be more closely related to one another than to any other group. So phyla can be merged or split if it becomes apparent that they are related to one another or not, a definition of a phylum based on body plan has been proposed by paleontologists Graham Budd and Sören Jensen. By Budd and Jensens definition, a phylum is defined by a set of shared by all its living representatives. This approach brings some small problems—for instance, ancestral characters common to most members of a phylum may have been lost by some members, also, this definition is based on an arbitrary point of time, the present. However, as it is based, it is easy to apply to the fossil record. A greater problem is that it relies on a decision about which groups of organisms should be considered as phyla. However, proving that a fossil belongs to the group of a phylum is difficult. Furthermore, organisms in the group of a phylum can possess the body plan of the phylum without all the characteristics necessary to fall within it. This weakens the idea that each of the phyla represents a body plan. A classification using this definition may be affected by the chance survival of rare groups. Representatives of many modern phyla did not appear until long after the Cambrian, the kingdom Plantae is defined in various ways by different biologists. All definitions include the living embryophytes, to which may be added the two green algae divisions, Chlorophyta and Charophyta, to form the clade Viridiplantae. The table below follows the influential Cavalier-Smith system in equating Plantae with Archaeplastida, a group containing Viridiplantae, the definition and classification of plants at the division level also varies from source to source, and has changed progressively in recent years
4.
Parasitoid
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A parasitoid is an organism that spends a significant portion of its life history attached to or within a single host organism in a relationship where the host is ultimately killed. Thus, parasitoidy is an evolutionary strategy to typical parasitism. There are parasitoids in a variety of taxa, including microbial diseases, plants, crustaceans, insects. Especially among the Hymenoptera, ichneumons and many wasps are highly specialised for a way of life. Some parasitoidal wasps are used in biological pest control, the term parasitoid was coined in 1913 by the Swedo-Finnish writer Odo Morannal Reuter, and adopted in English by his reviewer, William Morton Wheeler. Reuter used it to describe the strategy where the parasite develops in or on the body of a single host individual, eventually killing that host, since that time, the concept has been variously generalised and widely applied. These are adaptive peaks, with possible intermediate strategies. Parasitoids eventually kill their host, typically before it can produce offspring, a nonlethal parasitic organism, especially if it is a fungus, is sometimes termed a biotroph, while a parasitoidal fungus may be called a necrotroph. Idiobiont parasitoids prevent further development of the host after initially immobilizing it, koinobiont parasitoids allow the host to continue its development while feeding upon it, and may parasitise any host life stage. There is no separation between conventional parasitism and parasitoidy. For example, blood-sucking mites sometimes overwhelm nestlings of birds such as swallows to the point that the birds cannot fledge successfully. At the opposite extreme, parasitoidy grades into predation, differences between various hunting wasps provide convenient illustrations. Predatory social wasps hunt flies, caterpillars and the like, grab them, butcher them, carry them home and feed them to their young. Similarly, some solitary wasps such as beewolves, sting prey, sometimes fatally, before saving it, usually entire, in contrast, the best-known protelean solitary hunting wasps sting prey to paralyse it before storing it for the young in the nest. Other wasps paralyse prey in the plant or other environment in which it feeds, before laying eggs nearby, some insect parasitoids lay their eggs where the larvae must locate the prey for themselves when they hatch from the eggs. Examples include flies in the families Tachinidae and Bombyliidae, often with sophisticated physiological, in another strategy, some parasitoids influence the hosts behaviour in ways that favour the propagation of the parasitoid, often at the cost of the hosts life. Similarly, as strepsipteran parasitoids of ants mature, they cause the hosts to climb high on grass stalks, positions that are risky, but favour the emergence of the strepsipterans. Other species of endoparasitoids cause infected woodlice and land Amphipoda such as Talitroides to run about in the open by day, the rabies virus affects the hosts central nervous system, eventually killing it, but perhaps helping to disseminate the virus by modifying the hosts behaviour
5.
Nematode
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The nematodes or roundworms constitute the phylum Nematoda. They are an animal phylum inhabiting a broad range of environments. Nematodes are classified along with insects and other moulting animals in the clade Ecdysozoa, Nematodes have successfully adapted to nearly every ecosystem from marine to fresh water, to soils, and from the polar regions to the tropics, as well as the highest to the lowest of elevations. They are found in part of the earths lithosphere, even at great depths below the surface of the Earth in gold mines in South Africa. They represent 90% of all animals on the ocean floor, the many parasitic forms include pathogens in most plants and animals. The location of towns would be decipherable, since for every massing of human beings there would be a corresponding massing of certain nematodes, trees would still stand in ghostly rows representing our streets and highways. In 1758, Linnaeus described some nematode genera, then included in Vermes, the name of the group Nematoda, informally called nematodes, came from Nematoidea, originally defined by Karl Rudolphi, from Ancient Greek νῆμα and -eiδἠς. It was treated as family Nematodes by Burmeister, at its origin, the Nematoidea erroneously included Nematodes and Nematomorpha, attributed by von Siebold. Along with Acanthocephala, Trematoda and Cestoidea, it formed the obsolete group Entozoa and they were also classed along with Acanthocephala in the obsolete phylum Nemathelminthes by Gegenbaur. In 1861, K. M. Diesing treated the group as order Nematoda, in 1877, the taxon Nematoidea, including the family Gordiidae, was promoted to the rank of phylum by Ray Lankester. In 1919, Nathan Cobb proposed that nematodes should be recognized alone as a phylum and he argued they should be called nema in English rather than nematodes and defined the taxon Nemates, listing Nematoidea sensu restricto as a synonym. Since Cobb was the first to all but nematodes from the group, some sources consider the valid taxon name to be Nemates or Nemata. The phylogenetic relationships of the nematodes and their close relatives among the protostomian Metazoa are unresolved, traditionally, they were held to be a lineage of their own but in the 1990s, they were proposed to form the group Ecdysozoa together with moulting animals, such as arthropods. The identity of the closest living relatives of the Nematoda has always considered to be well resolved. Morphological characters and molecular phylogenies agree with placement of the roundworms as a taxon to the parasitic Nematomorpha. Together with the Scalidophora, the Nematoida form the clade Cycloneuralia, the Cycloneuralia or the Introverta—depending on the validity of the former—are often ranked as a superphylum. Due to the lack of knowledge regarding many nematodes, their systematics is contentious, an earliest and influential classification was proposed by Chitwood and Chitwood—later revised by Chitwood—who divided the phylum into two—the Aphasmidia and the Phasmidia. These were later renamed Adenophorea and Secernentea, respectively, the Secernentea share several characteristics, including the presence of phasmids, a pair of sensory organs located in the lateral posterior region, and this was used as the basis for this division
6.
Morphology (biology)
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Morphology is a branch of biology dealing with the study of the form and structure of organisms and their specific structural features. This includes aspects of the appearance, i. e. external morphology, as well as the form and structure of the internal parts like bones and organs. This is in contrast to physiology, which deals primarily with function, Morphology is a branch of life science dealing with the study of gross structure of an organism or taxon and its component parts. The word morphology is from the Ancient Greek don, morphé, meaning form, among other important theorists of morphology are Lorenz Oken, Georges Cuvier, Étienne Geoffroy Saint-Hilaire, Richard Owen, Karl Gegenbaur and Ernst Haeckel. In English-speaking countries, the term molecular morphology has been used for time for describing the structure of compound molecules, such as polymers. Comparative Morphology is analysis of the patterns of the locus of structures within the plan of an organism. Functional Morphology is the study of the relationship between the structure and function of morphological features, experimental Morphology is the study of the effects of external factors upon the morphology of organisms under experimental conditions, such as the effect of genetic mutation. Anatomy is a branch of morphology that deals with the structure of organisms, most taxa differ morphologically from other taxa. Typically, closely related taxa differ much less than more distantly related ones, cryptic species are species which look very similar, or perhaps even outwardly identical, but are reproductively isolated. Conversely, sometimes unrelated taxa acquire a similar appearance as a result of convergent evolution or even mimicry, in addition, there can be morphological differences within a species, such as in Apoica flavissima where queens are significantly smaller than workers. A further problem with relying on morphological data is that what may appear, morphologically speaking, the significance of these differences can be examined through the use of allometric engineering in which one or both species are manipulated to phenocopy the other species. Invention and development of microscopy enable the observation of 3-D cell morphology with both spatial and temporal resolution. The dynamic processes of cell morphology which are controlled by a complex system play an important role in varied important biological process, such as immune. Comparative anatomy Insect morphology Morphometrics Neuromorphology Phenetics Phenotype Phenotypic plasticity Plant morphology
7.
Larva
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A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a phase of their life cycle. The larvas appearance is very different from the adult form. A larva often has unique structures and organs that do not occur in the adult form and their diet may also be considerably different. Larvae are frequently adapted to separate from adults. For example, some such as tadpoles live almost exclusively in aquatic environments. By living in an environment, larvae may be given shelter from predators. Animals in the stage will consume food to fuel their transition into the adult form. In some species like barnacles, adults are immobile but their larvae are mobile, some larvae are dependent on adults to feed them. In many eusocial Hymenoptera species, the larvae are fed by female workers, in Ropalidia marginata the males are also capable of feeding larvae but they are much less efficient, spending more time and getting less food to the larvae. The larvae of species can become pubescent and do not develop further into the adult form. This is a type of neoteny and it is a misunderstanding that the larval form always reflects the groups evolutionary history. This could be the case, but often the stage has evolved secondarily. In these cases the form may differ more than the adult form from the groups common origin. Within Insects, only Endopterygotes show different types of larvae, several classifications have been suggested by many entomologists, and following classification is based on Antonio Berlese classification in 1913. There are four types of endopterygote larvae types, Apodous larvae - no legs at all and are poorly sclerotized. Based on sclerotization, three forms are recognized. Eucephalous - with well sclerotized head capsule, found in Nematocera, Buprestidae and Cerambycidae families
8.
Parasitism
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In biology/ecology, parasitism is a non-mutual relationship between species, where one species, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred primarily to organisms visible to the naked eye, Parasites can be microparasites, which are typically smaller, such as protozoa, viruses, and bacteria. Examples of parasites include the plants mistletoe and cuscuta, and animals such as hookworms, unlike predators, parasites typically do not kill their host, are generally much smaller than their host, and will often live in or on their host for an extended period. Both are special cases of consumer-resource interactions, Parasites show a high degree of specialization, and reproduce at a faster rate than their hosts. Classic examples of parasitism include interactions between vertebrate hosts and tapeworms, flukes, the Plasmodium species, and fleas, parasitism differs from the parasitoid relationship in that parasitoids generally kill their hosts. Parasites reduce host biological fitness by general or specialized pathology, such as parasitic castration and impairment of secondary sex characteristics, Parasites increase their own fitness by exploiting hosts for resources necessary for their survival, e. g. food, water, heat, habitat, and transmission. Although parasitism applies unambiguously to many cases, it is part of a continuum of types of interactions between species, rather than an exclusive category, in many cases, it is difficult to demonstrate harm to the host. In others, there may be no apparent specialization on the part of the parasite, coined in English in 1611, the word parasitism comes from the Greek παρά + σιτισμός feeding, fattening. Parasites are classified based on their interactions with their hosts and on their life cycles, an obligate parasite is totally dependent on the host to complete its life cycle, while a facultative parasite is not. A direct parasite has one host while an indirect parasite has multiple hosts. For indirect parasites, there always be a definitive host. Parasites that live on the outside of the host, either on the skin or the outgrowths of the skin, are called ectoparasites and those that live inside the host are called endoparasites. Endoparasites can exist in one of two forms, intercellular parasites or intracellular parasites, intracellular parasites, such as protozoa, bacteria or viruses, tend to rely on a third organism, which is generally known as the carrier or vector. The vector does the job of transmitting them to the host, an example of this interaction is the transmission of malaria, caused by a protozoan of the genus Plasmodium, to humans by the bite of an anopheline mosquito. Those parasites living in a position, being half-ectoparasites and half-endoparasites, are called mesoparasites. An epiparasite is one that feeds on another parasite and this relationship is also sometimes referred to as hyperparasitism, exemplified by a protozoan living in the digestive tract of a flea living on a dog. Social parasites take advantage of interactions between members of social organisms such as ants, termites, and bumblebees, an extreme example of social parasitism is the ant species of Tetramorium inquilinum of the Alps, which spend their whole lives on the back of Tetramorium host ants. With tiny and deprecated bodies they have evolved for one single task, if they fall off, they most likely would not have the strength to climb back on top of another ant, and eventually they will die
