The Protozoans

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The Protozoans
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11.1 Emergence of Eukaryotes
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What is a eukaryote?
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What is a eukaryote? An organism composed of one
or more cells containing visible evidence of
nuclei and organelles.
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How did eukaryotes evolve?
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How did eukaryotes evolve? cellular symbiosis
among prokaryotic cells
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What is a symbiosis?
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What is a symbiosis? When two dissimilar
organisms live together and form an intimate and
life-sustaining relationship that is mutually
beneficial.
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What is a prokaryote?
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What is a prokaryote? A cellular organism (such
as bacterium or blue-green alga) that does not
have a distinct, membrane-bound nucleus.
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How did Cellular Symbiosis happen?
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How did Cellular Symbiosis happen? Since 1)
Apparently, the first cells to appear in the
fossil record (3.5 billion years ago) were
bacteria-like and prokaryotic
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How did Cellular Symbiosis happen? Since 1)
Apparently, the first cells to appear in the
fossil record (3.5 billion years ago) were
bacteria-like and prokaryotic AND 2)
Eukaryotic cells have organelles and a
nucleus,
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Cellular Symbiosis Scientists postulate or
hypothesize that The origin of complex
eukaryotic cells was most likely a type of
symbiosis among prokaryotic cells.
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Cellular Symbiosis Scientists postulate or
hypothesize that The origin of complex
eukaryotic cells was most likely a type of
symbiosis among prokaryotic cells. This may have
involved aerobic bacteria which were engulfed by
anaerobic bacteria that were unable to tolerate
the increasing oxygen (anaerobic) in the
atmosphere caused by photosynthetic bacteria.
These engulfed aerobic bacteria had the necessary
enzymes for deriving energy in the presence of
oxygen and may have become the mitochondria found
in most modern eukaryotic cells.
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Similarly, Scientists hypothesize
that Engulfed photosynthetic bacteria evolved
into chloroplasts which are the descendants of
the green algae lineage, later giving rise to
multicellular plants.
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Protozoa are a diverse assemblage with mixed
characteristics a. They lack a cell wall,
unlike plants b. They have at least one motile
stage in the life cycle. c. Most ingest their
food.
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Contributions to Biological Complexity 1.
Protozoa have intracellular specialization or
organization of organelles in cells.
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Contributions to Biological Complexity 1.
Protozoa have intracellular specialization or
organization of organelles in cells. 2. Cells
may have distinct functions some colonial
protozoa have separate somatic and reproductive
zooids.
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Contributions to Biological Complexity 1.
Protozoa have intracellular specialization or
organization of organelles in cells. 2. Cells
may have distinct functions some colonial
protozoa have separate somatic and reproductive
zooids. 3. Asexual reproduction occurs by mitotic
division.
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Contributions to Biological Complexity 1.
Protozoa have intracellular specialization or
organization of organelles in cells. 2. Cells
may have distinct functions some colonial
protozoa have separate somatic and reproductive
zooids. 3. Asexual reproduction occurs by mitotic
division. 4. Some have true sexual reproduction
with zygote formation.
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Contributions to Biological Complexity 5.
Responses to stimuli represent the simplest
reflexes and inborn behaviors known.
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Contributions to Biological Complexity 5.
Responses to stimuli represent the simplest
reflexes and inborn behaviors known. 6. Shelled
protozoa have the simplest exoskeletons.
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Contributions to Biological Complexity 5.
Responses to stimuli represent the simplest
reflexes and inborn behaviors known. 6. Shelled
protozoa have the simplest exoskeletons. 7.
Basic enzymes systems support all types of
nutrition autotrophic, saprozoic and holozoic.
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Contributions to Biological Complexity 5.
Responses to stimuli represent the simplest
reflexes and inborn behaviors known. 6. Shelled
protozoa have the simplest exoskeletons. 7.
Basic enzymes systems support all types of
nutrition autotrophic, saprozoic and
holozoic. 8. Many have developed means of
locomotion.
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General Features 1. Over 64,000 species are
named half are fossils.
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General Features 1. Over 64,000 species are
named half are fossils. 2. Although they are
unicellular organisms, protozoan cell organelles
are highly specialized.
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General Features 1. Over 64,000 species are
named half are fossils. 2. Although they are
unicellular organisms, protozoan cell organelles
are highly specialized. 3. They are ecologically
diverse, widely dispersed, but many are limited
to narrow environmental ranges.
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General Features 1. Over 64,000 species are
named half are fossils. 2. Although they are
unicellular organisms, protozoan cell organelles
are highly specialized. 3. They are ecologically
diverse, widely dispersed, but many are limited
to narrow environmental ranges. 4. They can be
fantastically numerous, forming gigantic ocean
soil deposits.
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General Features 5. About 10,000 are symbiotic in
or on animals or plants some are human disease
agents.
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General Features 5. About 10,000 are symbiotic in
or on animals or plants some are human disease
agents. 6. Some are colonial with multicellular
stages but have noncolonial forms.
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General Features 5. About 10,000 are symbiotic in
or on animals or plants some are human disease
agents. 6. Some are colonial with multicellular
stages but have noncolonial forms. 7. Protozoa
have only one non-reproductive cell type and
lack embryonic development embryonic
development is one of the criteria for metazoa.
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Characteristics of Protozoan Phyla 1. They are
unicellular with some colonial and multicellular
stages.
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Characteristics of Protozoan Phyla 1. They are
unicellular with some colonial and multicellular
stages. 2. Most are microscopic.
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Characteristics of Protozoan Phyla 1. They are
unicellular with some colonial and multicellular
stages. 2. Most are microscopic. 3. All
symmetries are present within members of the
group.
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Characteristics of Protozoan Phyla 1. They are
unicellular with some colonial and multicellular
stages. 2. Most are microscopic. 3. All
symmetries are present within members of the
group. 4. No germ layers are present.
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Characteristics of Protozoan Phyla 1. They are
unicellular with some colonial and multicellular
stages. 2. Most are microscopic. 3. All
symmetries are present within members of the
group. 4. No germ layers are present. 5. No
organs or tissues are formed, but specialized
organelles serve many of these functions.
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Characteristics of Protozoan Phyla 1. They are
unicellular with some colonial and multicellular
stages. 2. Most are microscopic. 3. All
symmetries are present within members of the
group. 4. No germ layers are present. 5. No
organs or tissues are formed, but specialized
organelles serve many of these functions. 6.
They include free-living, mutualistic, commensal
and parasitic forms.
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Characteristics of Protozoan Phyla 7. They move
by pseudopodia, flagella, cilia and they can
direct cell movements.
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the physiology of movement
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Pseudopodia in - Phylum Sarcomastigophora, Subp
hylum Sarcodina AMOEBA
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Cilia in - Phylum Ciliophora, Class
Oligohymenophora Genus PARAMECIUM
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Flagella in - Phylum Sarcomastigophora, Subphyl
um Mastigophora, Class Phytomastigophorea EUGL
ENA
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Characteristics of Protozoan Phyla 7. They move
by pseudopodia, flagella, cilia and they can
direct cell movements. 8. Most are naked, but
some have a simple endoskeleton or exoskeleton.
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Characteristics of Protozoan Phyla 7. They move
by pseudopodia, flagella, cilia and they can
direct cell movements. 8. Most are naked, but
some have a simple endoskeleton or
exoskeleton. 9. All types of nutrition are
present autotrophic, heterotrophic and
saprozoic.
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Characteristics of Protozoan Phyla 7. They move
by pseudopodia, flagella, cilia and they can
direct cell movements. 8. Most are naked, but
some have a simple endoskeleton or
exoskeleton. 9. All types of nutrition are
present autotrophic, heterotrophic and
saprozoic. 10. They can be aquatic or
terrestrial, and free-living, symbiotic or
parasitic.
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Characteristics of Protozoan Phyla 7. They move
by pseudopodia, flagella, cilia and they can
direct cell movements. 8. Most are naked, but
some have a simple endoskeleton or
exoskeleton. 9. All types of nutrition are
present autotrophic, heterotrophic and
saprozoic. 10. They can be aquatic or
terrestrial, and free-living, symbiotic or
parasitic. 11. Reproduction is asexual by
fission, budding or cysts or sexual by
conjugation or syngamy of gametes.
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Phytomastigophorea
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Phytomastigophorea
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Zoomastigophorea
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Sarcodina
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Slime molds
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Actinopoda
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Apicomplexa
Plasmodium and malaria
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ciliates