Features: Single cell animals, the body's structure is very simple, eat, move, will reproduce and die. The body is very small, mostly microscopic use of animals observed. Inhabit fresh water, sea water or body fluids of other animals were. such as amoeba. The propagation of protozoan Most free-living species are generally in favor of asexual reproduction in the environment to survive. Sexual reproduction is usually only bad environment, they are a means only, such as when the depletion of aquatic medium caused when normal cells can not survive. In amoebae and flagellates, only a limited line of sexually reproducing species have the ability; some species in their evolutionary history may never have the line of sexual reproduction, while other species may have lost the ability to mate. Both protozoa with sexual reproduction with reproductive (sex cells or gametes similar), but also differences with the more advanced reproductive (sex cells or gametes different). Free-living species of foraminifera are rare in both asexual and sexual reproduction of the species, they are by asexual reproduction of each organism produces many amoeba-like organisms, these organisms secrete around their physical surrounding chitin. When they mature, the turn many of the same gametes released into the sea; these gametes in pairs with each other, the secretion of hatching mass and mature, and repeat the process. Almost all of the ciliates can be sexual reproduction, a process called pairing, but can not form this way, the immediate increase in their number. Matching between different individuals contribute to the exchange of genetic material. The classification of protists Due to the current international is no commonly accepted classification of protists system, here is the classification system in accordance with jh postlethwait, the original organisms are divided into: animals, protists, plants protists, fungi protozoa.
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No. 2
Protozoans protozoan Protozoa species, sub-sector, collectively, including a large group of unicellular eukaryotic (with a clear nucleus) organisms. Protozoa are the simplest organisms. Although the form of a sub-sector, but not necessarily between them related. From a biological point of view, they do not belong to a natural group, but only together will be a large number of organisms only. There have been 65,000 total account of a variety of protozoa, of which more than half of fossils. Protozoa everywhere, from pole to pole most of the soil and aquatic habitats can be found in the trace. Most of the naked eye can not see. Symbiosis with other organisms, many species, native to the existing approximately 1 / 3 of the parasite. Because of modern electron microscopy techniques and new biochemical and genetic technology to provide more and more knowledge, help people understand a variety of native species and the relationship between groups, but also so often proved the previous classification is not correct of, and to require frequent amendments to the classification of protozoa. 1, the biological characteristics of protozoa Protozoa about 30 000 species, most of the single cell structure, a few types of single-cell synthesis groups. Classification system in the five circles, often attributed to protozoa separate native biosphere. It mainly has the following characteristics: (1) small body. The size of protozoa is generally between a few microns to tens of microns. However, there are a few relatively large protozoa. Such as insects and jade blue horn beetle, body length of up to 1cm ~ 3cm, there is a currency of insects, its shell diameter of 16cm. (2) generally constitute a single cell, is a group of some species. Single-cell protozoan is a whole body cell, as a complete organism, they are the same as multicellular animals, a variety of vital functions, such as stress, exercise, breathing, feeding, digestion, excretion, and reproductive and so on. Single-cell protozoan, of course there can be no differentiation between cells, but cell division occurs by the differentiation of a variety of cytoplasmic organelles to achieve the corresponding vital functions. For example, have flagella for movement, cilia, pseudopodia, feeding a cell mouth, pharynx cells, barbed wire defense bubble, adjust the osmotic pressure of a flexible foam body and so on. Is a group of some protozoa, but the general composition does not differentiate between groups of cells, each individual maintain their independence. (3) Original. Generally speaking protozoa of the lowest, most primitive animals, referring to their morphological structure and physiological function in animals of all types is the simplest, most primitive, the earliest ancestor of the animal kingdom reflects the type of features. Protozoa can be speculated from the earth the face of the earliest animal ancestors. Now the survival of various types of protozoa, is the experience of thousands of years evolved into the modern evolution of species. Therefore, the present must not be seen as other types of protozoan ancestor of animals. (4) has three kinds of nutrition. First, plant nutrition, photosynthesis, also known as nutrition, such as green Euglena, etc.; Second, animal nutrition, also known as phagocytosis nutrition, such as amoeba, paramecium, etc.; Third, permeability nutrition, also known as saprophytic nutrition, such as Cryptosporidium the parasite and so on. (5) When faced with adverse conditions, they form cysts themselves are separated with the adverse external environment, while lowering the level of metabolism is very low, in a dormant state. Wait until the right environmental conditions, the structure will grow accordingly, to resume a normal life. In addition, protozoa adaptable, they can survive in a variety of natural conditions, such as fresh water, salt water, hot springs, snow and ice so that the slurry plant, animal and human blood, lymph and other body fluids. 2, the classification of protozoa In protozoa door, according to campaign organelles, nuclei, and of nutrition can be divided into four classes: (1) Gang lamblia. Organelle movement is one or more flagella, such as green Euglena, clothing and trichomoniasis. (2) amoeba Gang. Organelle movement is pseudopodia pseudopodia feeding both functions, such as a large amoeba. (3) carinii Gang. No moving organelles, all parasitic life business, such as Plasmodium vivax. (4) ciliate classes. Organelle movement is the cilia, there are two nuclei, ie large core and small core, large nuclear and nutrition, small nuclear and reproduction, such as Paramecium caudatum. 3, protozoan reproduction Most free-living species are generally in favor of asexual reproduction in the environment to survive. Sexual reproduction is usually only bad environment, they are a means only, such as when the depletion of aquatic medium caused when normal cells can not survive. In amoebae and flagellates, only a limited line of sexually reproducing species have the ability; some species in their evolutionary history may never have the line of sexual reproduction, while other species may have lost the ability to mate. Both protozoa with sexual reproduction with reproductive (sex cells or gametes similar), but also differences with the more advanced reproductive (sex cells or gametes different). Free-living species of foraminifera are rare in both asexual and sexual reproduction of the species, they are by asexual reproduction of each organism produces many amoeba-like organisms, these organisms secrete around their physical surrounding chitin. When they mature, the turn many of the same gametes released into the sea; these gametes in pairs with each other, the secretion of hatching mass and mature, and repeat the process. Almost all of the ciliates can be sexual reproduction, a process called pairing, but can not form this way, the immediate increase in their number. Matching between different individuals contribute to the exchange of genetic material. Protozoa and human relations Protozoa, although very small, it is difficult to observe with the naked eye, but these animals are directly or indirectly, have a close relationship with humans. Some of the benefit of humanity, and some harmful. For example: paramecium can devour bacteria, purify the water; sun worms, insects bell bait fish can be done; dysentery parasite, dysentery who will be within the amoeba dysentery.
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Wikipedia Daquan
Protozoa protozoa Protozoa (protozoa) in a native biological A sub-sector is mainly a class of single-cell eukaryotes. Known to about 6.5 Million, half of which is a fossil. There are 10,000 kinds of extant species is about Parasitic. According to modern classification system, protozoa Asian community for 7 doors. Queensland Sis of the original protozoa belonging to the four doors: the door meat foot flagella (Sarco- mast mound ophora): such as the amoeba, flagellates. Top gate complex (Apicomplexa): such as cluster worms, coccidia. Nosema door (Micro. spora): If Nosema (see photo). Ciliates door (Ciliphoi'a): Such as ciliates. Micro spores to insect Spodoptera litura The figure Nosema litura ~ Fresh spores (POM legal tablets, 1 000 ×). The figure Nosema litura ~ sub ultrastructure. N: nucleus; PF: polar tube. Protozoan infection of insects, most of the eggs by mouth or spread by a small number of Parasitoid ovipositor spread. Sent into the body cavity, in suitable conditions Insect cells infected with the intestinal wall, fat body, Malpighian tubules and haemolymph and other tissues. Protozoa can be asexual reproduction and sexual reproduction. Asexual reproduction Are: ① binary fission and budding, that is, a mother cell into two new individuals; ② many-body fission, the nucleus divided repeatedly to form a multi-core, and then the whole Protoplasm of cells separated by the formation of multiple new individual. Sexual reproduction is After meiosis, gamete fusion with the shape or contour form a zygote, zygote Further division. Generally only a parasitic insect pathogenic protozoa Appropriate development consistent with the temperature usually associated with insect hosts, 35oC above the development Inhibition. Protozoa spores or hold sac in the insect body or in wet Can survive for months. In nature, pathogenic protozoa in the regulation of certain insects Populations of important factors, such as micro-spore worms, insects, etc. After the new cluster Large number of deaths caused by insects in nature. In particular, insect spores of micro-Yu The natural infection rate of 40 to 90%; most insects, at least by one Spore worm infection, but because of the role of slow, generally as a comprehensive Management and long-term prevention measures. Some species, such as micro-locusts Insects (Nose flail locustae) has been used as microbial insecticides in the United States Book production. Instead of silkworm and bee gave Pebrine sericulture and Industry significant losses. (Xie Wei months Most soil 'Micro-governance sub-borer pest in the bee note
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English Expression
n.: protoplast, protozoa, protozoans, protozoon, protista, any of a large group of very small, usu one-celled, living things, that can be seen only under a microscope, (zoology) plotozoa