Here is a term paper on ‘Protozoans’.Find paragraphs, long and short term papers on ‘Protozoans’ especially written for college and medical students.
Term Paper on Protozoans
Term Paper Contents:
- Term Paper on Chlamydomonas
- Term Paper on Noctiluca
- Term Paper on Trichomonas
- Term Paper on Crysamoeba
- Term Paper on Proterospongia
- Term Paper on Collozoum
- Term Paper on Cryptomonas
- Term Paper on Giardia
- Term Paper on Volvox
- Term Paper on Arcella
- Term Paper on Ceratium
- Term Paper on Radiolarian Ooze
- Term Paper on Nyctotherus
- Term Paper on Stentor
- Term Paper on Trichonympha
- Term Paper on Clthrulina
- Term Paper on Sarcocystis
- Term Paper on Opalina
- Term Paper on Balantidium
Term Paper on Protozoans # 1. Chlamydomonas:
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Chlamydomonas is a typical genus of the order Phytomonadida. It is microscopic, unicellular and solitary individual, found in stagnant freshwater ponds. It is void or flattened body which is surrounded by a thick and delicate cellulose cell wall or capsule. It bears two long flagella, each arising from a blepharoplast in cytoplasm.
The cytoplasm include a vesicular nucleus, cup-shaped chloroplast, with a pyrenoid, a red stigma, a pair of small contractile vacuoles and reserve food granules as starch and oil droplets. Mainly holophytic type of nutrition but osmotrophic tendency is also seen. Asexual reproduction is by binary fission, often in palmella stage. Isogamy and is some case, anisogamy represents the sexual reproduction.
Term Paper on Protozoans # 2. Noctiluca:
Noctiluca is a marine and pelagic dinoflagellate, occurring in abundance on the water surface near shores. Its body is spherical body, naked, jelly-like and slightly pink in colour. There is a large pouch-like cytostome is present mid-ventrally leading into an elongated cytopharynx, which bears a small delicate flagellum and a large motile tentacle.
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Cytoplasm contains number of vacuoles at the periphery, but is dense centrally which contains a single nucleus. Locomotion is affected by the locomotors tentacle. Nutrition is exclusively holozoic in the absence of chloroplasts. Reproduction takes place by binary fission and multiple fissions (sporulation).
During sporulation, cytoplasm forms a multinucleate surface disc, which by exogenous budding gives rise to numerous uninucleate and uniflagellate swarmers or spores. These spores behave as luciferin which under the influence of an enzyme, luciferase, emit light. Nutriluca is very significant due to its characteristics of phosphorescent or emitting light.
Term Paper on Protozoans # 3. Trichomonas:
Trichomonas is a multiflagellate and the most common endoparasite of invertebrates as well as vertebrates. Its body is roughly egg-shaped or pear-shaped, slightly tapering posteriorly. Four at the anterior end four flagella arise from a group of basal bodies forming the basal complex. The recurrent or trailing flagellum is directed posteriorly bordering an undulating membrane.
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Two large striated parabasal fibres arise from the basal body complex. A contractile fibre costa runs along the line of attachment of undulating membrane. Body is supported by a central red or cylinder of microtubules, the axostyle. If frequently projects from the posterior end of body as spike and serves to anchor the animal while it feeds. Endoplasm contains an oval nucleus with few nucleoli.
Ventrally present a cytostome is present at the broad anterior end which is used for ingestion while feeding holozoically. Saprozoic mode feeding is also met with. Reproduction is exclusively by longitudinal binary fission.
Pathogenic species of Trichomonas are T. tenax of mouth. T. hominis of colon and T. vaginalis of vagina of humans. Of other animals, T. foetus of cattle and T. gallinae of doves and pigeons are important. The disease caused by species of Trichomonas is named after the parasite as trichomoniasis.
Term Paper on Protozoans # 4. Crysamoeba:
It is found in fresh water. Its body is egg shaped while swimming but it turns amoeboid when on substratum. Locomotion occurs through single flagellum. There are one nucleus, two or more contractile vacuoles and two yellow chromatophores in the protoplasm. Cytopharynx and skeleton remain absent. Nutrition is holophytic or hologoic.
Term Paper on Protozoans # 5. Proterospongia:
It appears as free living flagellate. There are present a gelatinous matrix of irregular shape in Proterospongias in which zooids remain embedded and form colony. A zooid is an oval cell with a transparent collar at one end through which a flagellum comes out. These collared goods remain embedded on the outside. There are also present some amoeboid zooids inside the matrix.
Term Paper on Protozoans # 6. Collozoum:
It is colonial in nature. Its body is spherical which measures about 3-4 cm in length. By means of perforated membrane, protoplasm is divided into intra-capsular and extra-capsular protoplasm. The vacuolated extra-capsular protoplasm is common to the entire colony having numerous central capsules embedded in it.
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Each central capsule indicates a zooid of the colony, which has a single nucleus. The central capsule undergoes repeated divisions, while the extra-capsular protoplasm does not divide. Reproduction occurs by means of merogony.
Term Paper on Protozoans # 7. Cryptomonas:
It makes its presence among algae containing chloroplasts in fresh and marine water. Its body remains covered by a thin pellicle and provided with two flagella and a gullet. There are present one nucleus and two usually green chromatophores in the protoplasm. Locomotion takes place by means of flagella. Nutrition is holophytic or saprophytic.
Term Paper on Protozoans # 8. Giardia:
Giardia, commonly nicknamed as the ‘Grand Old Man of the Intestine’, is another parasitic flagellate occurring in the intestine of man and other animals. Giardia intestinalis of small intestine of man possesses a bilateral symmetrical body measuring 10-18µ in length. Four flagella are on each side, all springing from the middle and hinder region of body.
Basal granules of foremost flagella are interconnected which are connected with a pair of conspicuous vesicular nuclei lying just posterior to them. A single axostyle forms the longitudinal axis of body. A parabasal body is also conspicuous. Reproduction takes places in human intestine by longitudinal binary fission. Infection is by uninucleate cysts which pass out in faeces and infect other persons through contaminated food and water.
Term Paper on Protozoans # 9. Volvox:
Volvox is a beautiful, colonial phytomonad commonly found in freshwater ponds and lakes. Colony looks like a small green, hollow ball filled with a watery jelly. The sphere contains thousands of zooids, arranged in a single peripheral layer connected together. Each zooid has 2 flagella, 2 or more contractile vacuoles, a large cup-shaped chloroplast, a single nucleus, a red stigma but no gullet.
Colony swims by rolling due to combined action of flagella. Nutrition is holophytic. Colony increases in size by binary fission of the surface somatic cells. Asexual reproduction takes place from reproductive zooids, mostly situated in the posterior part of colony.
Term Paper on Protozoans # 10. Arcella:
Arcella is commonly present in stagnant fresh water containing much vegetation and also in moist forest soils. It secretes a yellow to brown, thick, hard, transparent and hemispherical or disc-shaped shell or test around itself and carries it along as it moves. The shell is made of pseudochitin, a proteinous substance containing silica and iron.
It is finely sculptured and arched above but the ventral surface shows an inverted funnel-like depression leading to a single central opening, the mouth or pylome. One to six small, hyaline, finger-like, simple or benched lobopodia are present extending through the pylome and serve as locomotory and feeding organelles. Body is attached to inner wall of test by ectoplasmic strands, known as epipodia.
Various reserve food particles, food vacuoles and contractile vacuoles are found in endoplasm. One or more vacuoles are said to be non-contractile and filled with a gas, to which probably the organism owes it buoyancy. Two vesicular nuclei are present in A. vulgaris. Asexual reproduction takes place by binary fission. Multiple fission is also found to occur during reproduction in some cases.
Term Paper on Protozoans # 11. Ceratium:
Ceratium is found in marine as well as freshwater. The microscopic flattened body is armored by thecal plates, which are sculptured with spines and pits. These are produced into an anterior and generally two posterior spines. The shell is grooved by a transverse and a longitudinal furrow each provided with a flagellum.
The deep transverse groove or annulus encircles the body and contains the transverse flagellum. The longitudinal groove or sulcus is provided with large locomotor sulcul flagellum. The cytoplasm contains a large oval nucleus, numerous chromatophores and a complex system of contractile vacuoles. The nutrition is mainly holophytic, but a few species may be holozoic also. The reproduction is by oblique binary fission. Cyst formation also occurs sometimes.
Term Paper on Protozoans # 12. Radiolarian Ooze:
Radiolaria are exclusively marine and planktonic Sarcodina, found mostly in deep sea, particularly the tropical Pacific, floating or drifting at varying depths. They resemble heliozoans their outer appearance, but their cytoplasm is divided by a perforated and chitinous membrane or central capsule, into an intra-capsular or inner medulla, and an extra-capsular or outer cortex.
Medulla contains one or more nuclei and oil globules. Cortex is vacuolated, pigmented and often contains yellow, unicellular and symbiotic algae. Numerous vacuoles filled with a light fluid give a frothy appearance to cytoplasm and reduce specific gravity of organism. Besides central capsule, extra capsular cytoplasm may contain scattered, siliceous spicules.
In majority, however, a hard, transparent and symmetrical skeleton of silica (SiO2) or strontium sulphate is present, often of bizarre shape and beauty. It usually forms an intricate lattice-work, through the opening of which are extended fine, stiff and ray-like pseudopodia, usually without conspicuous axial filaments.
When these animals die, their minute but hard skeletons sink to the sea-bottom and form the radiolarian ooze.
Their fossils are abundant in rocks such as flint and chert. They also constitute a part of the “Tripoli Stone”, used in abrasive powders for polishing metals.
Term Paper on Protozoans # 13. Nyctotherus:
Nyctotherus is the intestinal, endo-commensal of amphibians and some invertebrates. Its important species are N. cordiformis in rectum of frogs and N. ovalis in intestine of cockroaches. Slightly compressed body is oval measuring about 60-120μ in length. Outer surface bears longitudinal and slightly spiral rows of cilia.
On lateral side is a vestibule leading to cell-mouth or cytostome. It bears somewhat longer cilia. Cytoplasm includes a contractile vacuole, a macronucleus a micronucleus and food vacuoles. Cytopyge, a permanent pore for the egestion of food, is located at its hinder end. Nutrition is holozoic. Reproduction is by binary fission and conjugation.
Term Paper on Protozoans # 14. Stentor:
Stentor is a free-swimming or sessile ciliate, mostly found in pond water contaminated with sewage. The sessile form takes a funnel or trumpet-shaped appearance. Oral surface bears a broad vestibule leading into buccal cavity, which is lined by a row of membranelles. Buccal cavity leads into cytopharynx through a cytostome.
Macronucleus is greatly beaded or chained and several micronuclei lie close to it. A single contractile vacuole lies anteriorly and fed by a single and long radial canal. Nutrition is holozoic. Reproduction takes place by oblique binary fission and conjugation.
Term Paper on Protozoans # 15. Trichonympha:
Its body has complicated structure. The surface of entire cell remains covered by a large number of flagella which occurs in groups. Ectoplasm bears oblique fibres, an alveodor layer and transverse myonemes while endoplasm bears longitudinal myonemes. Trichonympha remains in symbiotic relationship with its host. It renders the cellulose of wood eaten by the termite digestible by termite without the flagellates wood is not digested by termites.
Term Paper on Protozoans # 16. Clthrulina:
It makes its presence in fresh water. Body remains enclosed in a perforated sphere of silica and provided with a stalk. It bears single nucleus. Reproduction occurs by the process of merogeny.
Term Paper on Protozoans # 17. Sarcocystis:
It is a parasite and makes its presence in vertebrates like rabbit, cattle, sheep, pig, rat, horse, reptiles and birds. Occasionally, it may also found in man. It makes a long spindle-shaped multinucleate cyst which is found embedded in the striped muscle fibres of the host. The masses of spindle shaped parasites form long, slender, cylindrical bodies with pointed ends known as Miescher’s or Rainey’s tubes. Within each tube a large number of sickle shaped spores are formed. These spores are known as Rainey’s corpuscles. Very little is known regularly the mode of transmission of this parasite.
Term Paper on Protozoans # 18. Opalina:
Opalina lives as an endoparasite or endocommensal in large intestine of Anura. Commonest species is O. ranarum which is found in rectum of frogs and toads. Its body is flattened, leaf-like and oval in outline. It may reach a length of about 1 mm, and may be seen with naked eyes. Thin but tough pellicle is uniformly covered by rows of innumerable and equal-sized cilia (flagella).
Between rows of cilia, pellicle is thrown into narrow longitudinal folds, supported by micro tubular fibrils. Mouth, gullet, cytopyge, food vacuoles and contractile vacuoles are absent. Opalina feeds by pinocytosis, ingesting liquid food content of rectum of host through general body surface.
A large number of small, spherical and similar nuclei are found every distributed in endoplasm, which also contains several minute spindle-like or ovoid granules of unknown character. Each nucleus is composed of both trophochromatin and idiochromatin.
During breeding season of host, Opalina undergoes transverse as well as longitudinal binary fission’s to produce small individuals, each with only three to six nuclei and few rows of cilia. These encyst and pass out in faeces of host. If cysts are swallowed by tadpoles, along with weeds, they hatch in rectum as gametocytes, which divide by a series of longitudinal fissions to form uninucleate, club-shaped gametes. These include small slender microgametes and large macrogametes. These conjugate in pairs to form zygotes which encyst for a while as zygocysts.
Term Paper on Protozoans # 19. Balantidium:
Balantidium is a trichostomatid ciliate parasite, inhabiting the intestine of man, pigs, sheep, guinea pigs, camels opossums, ostriches, fish, cockroaches, etc. They are present in large numbers in rectal contents of frog. Of about 50 species of Balantidium only one species, B. colid, infects man.
The organism is large and ovoid. Entire outer surface is covered by longitudinal, slightly spiral rows of cilia. At the anterior end is a vestibule leading to the cell mouth or cytostome. It is lined by longer cilia. Cytoplasm includes two contractile vacuoles, a macronucleus and food vacuoles.
At the hinder end is a permanent pore or cytopyge for egestion of undigested residue. Nutrition is holozoic. The food is carried down vestibule into the forming food vacuole with a drop of water. Reproduction takes place by asexual binary fission. Infection takes place through contaminated food and water containing the parasite in encysted forms.