kingdom: protista protozoans - silverfalls.k12.or.us file3/7/2006 4 four major groups of protozoans...
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Kingdom: PROTISTA PROTOZOANS
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Kingdom: PROTISTA
• Single celled (unicellular), colonial or multicellular organisms
• Reproduce sexually or asexually• Three major categories:
– Protozoans - “first animals”– Algae – “plant-like”– Molds – “fungus-like”
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CHARACTERISTICS OF UNICELLULAR ORGAISMS:
• BACTERIA• KINGDOMS: Eubacteria &
Archaebacteria• CHARACTERISTICS:
– Cell Wall– No Nucleus– Tiny in size– Many cause disease– Reproduction – binary fission– Limited locomotion (movement)– Classification – based on shape
• PROTOZOANS• KINGDOM: Protista• Characteristics:
– No cell wall– Nucleus present– Larger than bacteria– Can cause disease– Reproduction:
• Binary fission• Conjugation• Spores
• Specialized Locomotion• Classification – based on locomotion
– Sarcodines (pseudopod)– Cilliates(cilia or little hairs)– Flagellates (flagella)– Sporozoans (spores)
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Four Major Groups of Protozoans
• 1. Sacrodines– Move by means of pseudopod
(“false foot”)– Some have shell-like
coverings• Example: Foraminiferons
– chambered outer shell made of calcium carbonate (limestone)
• Classic example: Amoeba
» Typical sacrodine» Blob-like body
form» Moves and feeds
by pseudopod
Amoeba
pseudopod
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Four Major Groups of Protozoans Cont…( Sacrodines Cont…)
• Amoeba feeding:Pseudopod traps food particleFood vacuole engulfs and releases digestive chemicals Digestive food is used and waste particles (including CO2) are eliminated through the cell membraneOxygen is absorbed through the cell membraneExcess water is eliminated through the Contractile Vacuole
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Four Major Groups of Protozoans Cont…. ( Sacrodines Cont…)
• Amoeba Reproduction:– Binary fission – parent cell
divides into two identical cells
• Amoeba also respond to changes in environment:– Light sensitive– Various chemical
responses
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Four Major Groups of Protozoans Cont…. Ciliates
2.Ciliates– Classic example:
Paramecium– Typical ciliate
structure– Covered with hair-like
projections called cilia– Cilia can be
specialized for feeding and locomotionParamecium
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Four Major Groups of Protozoans Cont…. (Ciliates cont…)
• Paramecium anatomy:– Pellicle – hard covering on
outer surface (“slipper” shape)
– Oral groove – indentation that cilia “sweep” food towards; Leads to gullet
– Gullet – funnel shape structure leading to food vacuole
– Food vacuole – moves through organism distributing food particles
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Four Major Groups of Protozoans Cont…. (Ciliates cont…)
• Two nuclei– Micronucleus: small
nucleus that controls reproduction
– Macronucleus: larger nucleus that controls other cell functions
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Four Major Groups of Protozoans Cont…. (Ciliates cont…)
• Reproduction:– Binary fission (splitting in
two)– Conjugation (sharing of
genetic material)• Two paramecium line up
and join together • Macronuclei
disappear;Micronuclei divide in two
• One micronuclei from each pair pass through tube joining paramecium together
• Paramecium separate and new micro and macro nuclei form
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Four Major Groups of Protozoans Cont…. Flagellates
• 3.Flagellates– Move by means of flagella (“whip-like”
structure)– Flagella move organism through watery
environment in which they live– Unicellular (one cell) and colonial (clusters of
cells)
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Four Major Groups of Protozoans Cont…. (Flagellates cont…)
Three main groups of flagellates:• 1. AUTOTROPHIC:
– Contain chlorophyll and are therefore able to make there own food
– Classic example: Volvox (also forms colonies)
Volvox
Daughter colony
Individuals
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Four Major Groups of Protozoans Cont…. (Flagellates cont…)
Three main groups of flagellates cont…:• 2.HETEROTROPHS:
– Can’t make own food– No chloroplasts– Usually parasites– Example:
Trypanosoma ssp.• Causes African
sleeping sickness
Trypanosoma ssp.
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Four Major Groups of Protozoans Cont…. (Flagellates cont…)
Three main groups of flagellates:• 3. Autotrophic and
Heterotrophic:– Classic example: Euglena
• Tiny oval shaped • One pointed end and one
round end• Rounded end with
flagellum and eyespot(reddish light sensitive structure)
• Moves towards light to capture energy to make own food (contain chloroplasts)
Euglena
flagella
nucleus
eyespot
•chloroplasts
PellicleParamylon body
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Four Major Groups of Protozoans Cont…. (Flagellates cont…)
Three main groups of flagellates cont…:• Reproduction:
– Binary fission (the long way)• Results in mirror images or symmetrical
“offspring”
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Four Major Groups of Protozoans Cont…. 4. Sporozoans
• Complicated life cycles with spores produce at some stage:– Spores:
• Contain hereditary material and a small amount of cytoplasm
• Can develop directly into mature Sporozoans
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Four Major Groups of Protozoans Cont…. Sporozoans cont…
• Classic example:– Plasmodium:
• Causes Malaria an infection of the bloodstream (destroys blood cells) common in tropical climates and spread by the Anophelesmosquito
– Mosquito acts as a VECTOR (carries malaria Sporozoans in its saliva from person to person)
– Can be treated with quinine