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26 Cards in this Set
- Front
- Back
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Sarcodines are holozoic. Holozoic means...
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eat living prey
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less common asexual reproduction of amoebae is by
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transverse binary fission
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briefly outline amoeboid movement using pseudopods
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cyclical conversion of ectoplasm into endoplasm
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ectoplasm (plasmagel)
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semirigid, fibrous outer shell
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endoplasm (plasmasol)
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fluid inner core of cytoplasm
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uroid
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the posterior bulb found in some amoebae originally suspected to be involved in locomotion
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Fountain-zone theory (1970s)
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the tips of the pseydopods and cortex exert contractile pressure on the endoplasm pulling it forward
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More recent theory on amoebae locomotion [3 parts]
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Protrusion
Attachment Traction |
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What is 'protrusion' in amoeboid movement?
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actin microfilaments are pushed forward by cortical tension
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What is 'attachment' in amoeboid movement?
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the actin connects to the substratum
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What is 'traction' in amoeboid movement?
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the bulk of the cytoplasm is drawn forward
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In psuedopodial movement, actin filaments are in what location?
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found in the cortex ectoplasm running parallel to the long axis of the cell
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In psudopodial movement, myosin microfilaments are in what location?
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found in the posterior region of the cell; the uroid region
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Most parasitic species of amoebae belong to this species
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Entamoeba (smaller than amoeba)
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All parasitic amoebae have _____ but none have _____.
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lobopodia; contractile vaculoes
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Lobopodia
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broad flat psedopodia
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Parasitic amoebae don't have contractile vacuoles because...
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they do not require to constantly pump out water because of their environment in the host
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Parasitic amoebae have distinguished granular endoplasm because
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they have one ore more nuclei
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Entamoeba hisolytica causes ____ and enters by ___
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causes amoebic dysntery; enters by means of ingestion through the mouth in the form of a cyst
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Entamoeba histolytica inhabits...
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the large intestine particularly the caecum and the upper colon
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Amoebic dysentery
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intestinal disease characterized by sever diarrhea, bloody stool and ulcers in the intestinal wall; may spread to the liver lungs or brain (abscesses) [Entamoeba histolytica]
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Cyst
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thick-walled, resistant resting stage in the life-cycle of some protists
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Acanthamoeba, Naegleria fowleri
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usually free-living but produce opportunistic infections (such as the eye)
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Facultative Amoebas
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able to live and survive under different environments (ie aerobic or anaerobic)
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Trophozoite stage
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feeding stage in the life-cycle of protozoa characterized by anaerobic metabolism
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Clade
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group consisting of a common ancestor
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