Transcript Phylum Apicomplexa

Protozoa
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By
–V.PARTHASARATHY
–Lecturer in Zoology
–Vivekananda College,
–Tiruvedakam West
Characteristics of Protozoa
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Unicellular Organization
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Since Protozoa are single celled they often rely on other
organisms for some necessities
Reproduction:
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Asexual:
1. binary fission: cytoplasmic division follows mitosis, producing
two organisms
2. budding:
3. multiple fission or schizogeny: cell or organism is split into many
new cells or organisms
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Sexual
Reproduction
Symbiosis:
an intimate association between two organisms
Three types of symbiosis:
1. Parasitism: one organism lives in or on a
second organism, called the host.
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the host is harmed, but usually survives
2. Commensalism: one organism benefits and
the other neither benefits nor is harmed
3. Mutualism: both organisms benefit from the
relationship
Protozoan Taxonomy
Phylum Sarcomastigophora
Subphylum Mastigophora
Subphylum Sarcodina
Phylum Apicomplexa
Phylum Ciliophora
SARCOMASTIGOPHORA
Phylum Sarcomastigophora:
18,000 species, largest protozoan phylum
Characteristics:
1. Unicellular or Colonial
2. Locomotion by flagella, pseudopodia, or
both
3. Autotrophic, saprozoic, or heterotrophic
4. Single type of Nucleus
5. Sexual Reproduction (usually)
LOCOMOTION
Subphylum Mastigophora:
locomotion by one or more flagella
Subphylum Sarcodina: locomotion and food
gathered by pseudopodia (false foot)
- includes the Amoeba
Pseudopodia
- temporary cell extension used for movement and
gathering food
Types:
1. Lobopodia: broad extensions used for locomotion
and engulfing food
2. Filopodia: provide constant two-way streaming that
delivers food in a conveyor belt fashion
3. Reticulopodia: similar to filopodia, except they
extend out and form net-like series of extensions
4. Axopodia: thin, filamentous and supported by a
central axis of microtubules
The AMOEBA
APICOMPLEXA
Phylum Apicomplexa:
Characterisitics:
1. All are parasites
2. Apical Complex for penetrating host cells
3. Single type of Nucleus
4. Usually No Cilia and Flagella
5. Life cycles that typically include asexual
and sexual phases
Malaria caused by Plasmodium
Phylum Ciliophora:
Characteristics:
1. Cilia for locomotion and for the
generation of feeding currents of water.
2. Relatively rigid pellicle and more or less
fixed shape
3. Distinct cytostome (mouth) Structure
4. Dimorphic nuclei, typically larger
macronuclei and one more smaller
micronuclei
Ciliophora
Locomotion: cilia
• Cilia are generally similar to flagella but are
much shorter, more numerous and widely
distributed over the surface of the organism
– cilia have evolved into more specialized structures
Trichocysts: used for protection, rodlike or oval
structures that can be discharged and stuck to
predators
Trichocysts
Body types
Nutrition:
• some ciliates possess an oral groove
• cilia sweep food particles down this groove
toward the cytopharynx where a food vacuole
forms
• some ciliates even possess an anal pore which
is used to remove waste from the organism
Genetic Control and Reproduction:
Ciliate have two kinds of Nuclei
1. Macronuclei: large polyploid nucleus that
regulates daily metabolic activities
2. Micronuclei: one or more small nucleus which
are genetic reserve of the cell
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Ciliates can reproduce asexually by transverse
binary fission and occasionally by budding
Ciliates can reproduce sexually by conjugation
Conjugation:
1. Random contact brings individuals of opposite
mating types together (called conjugants)
2. Meiosis results in four haploid pronuclei
3. Three pronuclei and the macronucleus degenerate.
Mitosis and mutual exchange of pronuclei is
followed by fusion of the pronuclei.
4. Conjugants separate. Nuclear divisions that restore
nuclear characteristics of species follow.
Cytoplasmic divisions may accompany these events
Conjugation