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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