mention important characters of phylum protozoa and porifera
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Poriferans are commonly called sponges.
These are multicellular organisms which are sessile/sedentary in nature.
Most of them are marine while a few are fresh water forms.
Body is cylindrical, asymmetrical or has radial symmetry.
Body wall is diploblastic which consists of an outer layer called pinacoderm and an inner layer called choanoderm.
The middle layer is called mesenchymewhich has various kinds of wandering amoebocytes.
Body wall contains numerous pores called ostia through which water enters in the body through a canal system into the central body cavity, called spongocoel.
The canal syytem mainky comprise of incurrent and excurrent canals which are lined with pinacocytes; and radial canalswhich are lined with choanocytes(flagellated cells).
Body also contains one or more openings called oscula (-um/singular) through which water passes out from the body.
Sponges feed on minute organisms and small organic particles which enter the body through water current and are ingested by the choanocytes.
Respiration takes place by diffusion of oxygen from water the flowing into the body.
Sponges have an exoskeleton which is made up of either spongin fibers or calcareous/siliceous spicules or a combination of both.
Excretory product, mainly ammonia, is released from the body through outgoing water current.
Protozoa :-
General Characteristics of Protozoa
Protozoa are eukaryotic microorganisms. Although they are often studied in zoology courses, they are considered part of the microbial world because they are unicellular and microscopic.
Protozoa are notable for their ability to move independently, a characteristic found in the majority of species. They usually lack the capability for photosynthesis, although the genus Euglena is renowned for motility as well as photosynthesis (and is therefore considered both an alga and a protozoan). Although most protozoa reproduce by asexual methods, sexual reproduction has been observed in several species. Most protozoal species are aerobic, but some anaerobic species have been found in the human intestine and animal rumen.
Protozoa are located in most moist habitats. Free-living species inhabit freshwater and marine environments, and terrestrial species inhabit decaying organic matter. Some species are parasites of plants and animals.
Protozoa play an important role as zooplankton, the free-floating aquatic organisms of the oceans. Here, they are found at the bases of many food chains, and they participate in many food webs.
Size and shape. Protozoa vary substantially in size and shape. Smaller species may be the size of fungal cells; larger species may be visible to the unaided eye. Protozoal cells have no cell walls and therefore can assume an infinite variety of shapes. Some genera have cells surrounded by hard shells, while the cells of other genera are enclosed only in a cell membrane.
Many protozoa alternate between a free-living vegetative form known as atrophozoite and a resting form called a cyst. The protozoal cyst is somewhat analogous to the bacterial spore, since it resists harsh conditions in the environment. Many protozoal parasites are taken into the body in the cyst form.
Most protozoa have a single nucleus, but some have both a macronucleus and one or more micronuclei. Contractile vacuoles may be present in protozoa to remove excess water, and food vacuoles are often observed.
Nutrition and locomotion. Protozoa are heterotrophic microorganisms, and most species obtain large food particles by phagocytosis. The food particle is ingested into a food vacuole. Lysosomal enzymes then digest the nutrients in the particle, and the products of digestion are distributed throughout the cell. Some species have specialized structures called cytostomes, through which particles pass in phagocytosis.
Many protozoal species move independently by one of three types of locomotor organelles: flagella, cilia, and pseudopodia. Flagella and cilia are structurally similar, having a “9-plus-2” system of microtubules, the same type of structure found in the tail of animal sperm cells and certain cells of unicellular algae. How a protozoan moves is an important consideration in assigning it to a group.
These are multicellular organisms which are sessile/sedentary in nature.
Most of them are marine while a few are fresh water forms.
Body is cylindrical, asymmetrical or has radial symmetry.
Body wall is diploblastic which consists of an outer layer called pinacoderm and an inner layer called choanoderm.
The middle layer is called mesenchymewhich has various kinds of wandering amoebocytes.
Body wall contains numerous pores called ostia through which water enters in the body through a canal system into the central body cavity, called spongocoel.
The canal syytem mainky comprise of incurrent and excurrent canals which are lined with pinacocytes; and radial canalswhich are lined with choanocytes(flagellated cells).
Body also contains one or more openings called oscula (-um/singular) through which water passes out from the body.
Sponges feed on minute organisms and small organic particles which enter the body through water current and are ingested by the choanocytes.
Respiration takes place by diffusion of oxygen from water the flowing into the body.
Sponges have an exoskeleton which is made up of either spongin fibers or calcareous/siliceous spicules or a combination of both.
Excretory product, mainly ammonia, is released from the body through outgoing water current.
Protozoa :-
General Characteristics of Protozoa
Protozoa are eukaryotic microorganisms. Although they are often studied in zoology courses, they are considered part of the microbial world because they are unicellular and microscopic.
Protozoa are notable for their ability to move independently, a characteristic found in the majority of species. They usually lack the capability for photosynthesis, although the genus Euglena is renowned for motility as well as photosynthesis (and is therefore considered both an alga and a protozoan). Although most protozoa reproduce by asexual methods, sexual reproduction has been observed in several species. Most protozoal species are aerobic, but some anaerobic species have been found in the human intestine and animal rumen.
Protozoa are located in most moist habitats. Free-living species inhabit freshwater and marine environments, and terrestrial species inhabit decaying organic matter. Some species are parasites of plants and animals.
Protozoa play an important role as zooplankton, the free-floating aquatic organisms of the oceans. Here, they are found at the bases of many food chains, and they participate in many food webs.
Size and shape. Protozoa vary substantially in size and shape. Smaller species may be the size of fungal cells; larger species may be visible to the unaided eye. Protozoal cells have no cell walls and therefore can assume an infinite variety of shapes. Some genera have cells surrounded by hard shells, while the cells of other genera are enclosed only in a cell membrane.
Many protozoa alternate between a free-living vegetative form known as atrophozoite and a resting form called a cyst. The protozoal cyst is somewhat analogous to the bacterial spore, since it resists harsh conditions in the environment. Many protozoal parasites are taken into the body in the cyst form.
Most protozoa have a single nucleus, but some have both a macronucleus and one or more micronuclei. Contractile vacuoles may be present in protozoa to remove excess water, and food vacuoles are often observed.
Nutrition and locomotion. Protozoa are heterotrophic microorganisms, and most species obtain large food particles by phagocytosis. The food particle is ingested into a food vacuole. Lysosomal enzymes then digest the nutrients in the particle, and the products of digestion are distributed throughout the cell. Some species have specialized structures called cytostomes, through which particles pass in phagocytosis.
Many protozoal species move independently by one of three types of locomotor organelles: flagella, cilia, and pseudopodia. Flagella and cilia are structurally similar, having a “9-plus-2” system of microtubules, the same type of structure found in the tail of animal sperm cells and certain cells of unicellular algae. How a protozoan moves is an important consideration in assigning it to a group.
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PROTOZOA..
3rd largest phylam
it includes unicellular eukaryotes where one celled body perform all biological activities like multicellular animal
holozoic nutrition
body level of organisation is protoplasmic level
these are considered as immortal
respiration and excretion take place by general body surface
PORIFERA
member of this phylam is commanly known as sponges
all ate aquetic and sessile
sponges are multicellular and having cellular level of organisation
respiration and excretion take place by general body surface through diffusion. .
hope it Will help you
3rd largest phylam
it includes unicellular eukaryotes where one celled body perform all biological activities like multicellular animal
holozoic nutrition
body level of organisation is protoplasmic level
these are considered as immortal
respiration and excretion take place by general body surface
PORIFERA
member of this phylam is commanly known as sponges
all ate aquetic and sessile
sponges are multicellular and having cellular level of organisation
respiration and excretion take place by general body surface through diffusion. .
hope it Will help you
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