Describe briefly the four major group of protozoa

Modern ultrastructural, biochemical, and genetic evidence has rendered the term protozoan highly problematic. For example, protozoan historically referred to a protozoan in formal protozoan is used informally in reference to nonfilamentous heterotrophic protists. Commonly known protozoans include representative Plasmodium. Features of protozoans Although protozoans are no longer recognized as a formal group in current biological classification systems, protozoan can still be useful as a strictly descriptive term. The protozoans are unified by their heterotrophic mode of nutrition, meaning that these organisms acquire Paramecium bursaria, have developed symbiotic relationships with eukaryotic Paulinella chromatophora remarkably appears to have acquired autotrophy via relatively recent endosymbiosis of a cyanobacterium (a Polytomella species and many Discover how individual cilia employ viscous drag to coordinate power and recovery strokes for locomotion The most important groups of free-living protozoans are found within several major evolutionary clusters of protists, including the ciliates (supergroup Chromalveolata), the lobose amoebae (supergroup Amoebozoa), the filose amoebae (supergroup Rhizaria), the cryptomonads (supergroup Chromalveolata), the excavates (supergroup Excavata), the opisthokonts (supergroup Opisthokonta), and the euglenids (Euglenozoa). These groups of organisms are important ecologically for their role in microbial nutrient cycles and are found in a ...

(a) Amoeboid protozoa: These organisms live in fresh water, sea water or moist soil. They move and capture their prey by putting out pseudopodia (false feet) as in Amoeba. Marine forms have silica shells on their surface. Some of them such as Entamoeba are parasites. (b) Flagellated protozoa: The members of this group are either free-living or parasitic. They have flagella. The parasitic forms cause diseases such as sleeping sickness. Example: Trypanosoma. (c) Ciliated protozoa: These are aquatic, actively proving organisms because of the presence of thousands of cilia. They have a cavity (gullet) that opens to the outside of the cell surface. The co-ordinated movement of rows of cilia causes the water laden with food to be steered into the gullet. Example: Paramecium (d) Sporozoans: This includes diverse organisms that have an infectious spore-like stage in their life cycle. The most notorious is Plasmodium which causes malaria which has a staggering effect on human population. There are 4 major groups of protozoa. (1) Amoeboid protozoans or sarcodines They are unicellular, jelly-like protozoa found in fresh or seawater and in moist soil. Their body lacks a periplast. Therefore, they may be naked or covered by a calcareous shell. They usually lack flagella and have temporary protoplasmic outgrowths called pseudopodia for locomotion. These pseudopodia or false feet help in movement and capturing prey. They include free-living forms such as Amoeba or parasitic forms such as...

Protozoa Further analysis of kingdom Protista has suggested the need for restructuring phylogenic classification. Genetic and morphological research has led to subdividing the Protista kingdom into numerous separate kingdoms, each with its own lineage of protist. In truth, the classification of the protists remains in flux. This chapter provides descriptions of representative members of the Protista group and their roles in our lives and the environment, using the still-accepted kingdom and phyla nomenclature. Members of the kingdom Protista are a highly varied group of organisms, all of which are eukaryotic. In addition, protists are unicellular or, in some cases, colonial. Many species are autotrophs, creating their own food, while others are heterotrophs, feeding on organic matter. Many species are nonmotile, but the majority of protists are able to move by various means. Many protists have contractile vacuoles, which help them to remove excessive amounts of water from their cytoplasm. The kingdom Protista includes the protozoa, slime molds, and algae. Protozoa can be divided into four phyla based on their locomotion: Mastigophora, Sarcodina, Ciliophora, and Sporozoa. Mastigophora Members of the phylum Mastigophora move about by using one or more whiplike flagella. The genus Euglena contains flagellated species. Members are freshwater protists with typical eukaryotic properties, including two flagella, reproduction by mitosis, and flexible nutritional requirements. Eugl...

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Protozoa Further analysis of kingdom Protista has suggested the need for restructuring phylogenic classification. Genetic and morphological research has led to subdividing the Protista kingdom into numerous separate kingdoms, each with its own lineage of protist. In truth, the classification of the protists remains in flux. This chapter provides descriptions of representative members of the Protista group and their roles in our lives and the environment, using the still-accepted kingdom and phyla nomenclature. Members of the kingdom Protista are a highly varied group of organisms, all of which are eukaryotic. In addition, protists are unicellular or, in some cases, colonial. Many species are autotrophs, creating their own food, while others are heterotrophs, feeding on organic matter. Many species are nonmotile, but the majority of protists are able to move by various means. Many protists have contractile vacuoles, which help them to remove excessive amounts of water from their cytoplasm. The kingdom Protista includes the protozoa, slime molds, and algae. Protozoa can be divided into four phyla based on their locomotion: Mastigophora, Sarcodina, Ciliophora, and Sporozoa. Mastigophora Members of the phylum Mastigophora move about by using one or more whiplike flagella. The genus Euglena contains flagellated species. Members are freshwater protists with typical eukaryotic properties, including two flagella, reproduction by mitosis, and flexible nutritional requirements. Eugl...

(a) Amoeboid protozoa: These organisms live in fresh water, sea water or moist soil. They move and capture their prey by putting out pseudopodia (false feet) as in Amoeba. Marine forms have silica shells on their surface. Some of them such as Entamoeba are parasites. (b) Flagellated protozoa: The members of this group are either free-living or parasitic. They have flagella. The parasitic forms cause diseases such as sleeping sickness. Example: Trypanosoma. (c) Ciliated protozoa: These are aquatic, actively proving organisms because of the presence of thousands of cilia. They have a cavity (gullet) that opens to the outside of the cell surface. The co-ordinated movement of rows of cilia causes the water laden with food to be steered into the gullet. Example: Paramecium (d) Sporozoans: This includes diverse organisms that have an infectious spore-like stage in their life cycle. The most notorious is Plasmodium which causes malaria which has a staggering effect on human population. There are 4 major groups of protozoa. (1) Amoeboid protozoans or sarcodines They are unicellular, jelly-like protozoa found in fresh or seawater and in moist soil. Their body lacks a periplast. Therefore, they may be naked or covered by a calcareous shell. They usually lack flagella and have temporary protoplasmic outgrowths called pseudopodia for locomotion. These pseudopodia or false feet help in movement and capturing prey. They include free-living forms such as Amoeba or parasitic forms such as...