Protists By: Lauren Kelly, Katie Chicojay, Jessie Sandberg, and Kirsten Gronlund

Eukaryotes evolved between 2 to 2.25 billion years ago chromosomes located in membrane-enclosed nucleus organelles o membrane-bound o specialized form and function generally larger than prokaryotic cells

Protista Kingdom eukaryotic most diverse kingdom- all organisms that are not plants, animals, or fungi paraphyletic- not grouped by evolutionary relatedness most are aquatic o may live anywhere damp

Biology of Protists structure o most unicellular o some colonial o some multicellular Nutritionally diverse o photoautotrophs o heterotrophs o mixotrophs reproduction o sexually (meiosis & syngamy) o asexually cyst formation o forms when a protist is in harsh environment o dormant form of cell with resistant outer covering locomotion o whip-like flagella o blob-like appendages o cilia

Endosymbiosis - Process in which a unicellular organism engulfs another cell o Engulfed cell becomes an endosymbiont and ultimately an organelle in host Secondary Endosymbiosis - Process in which the product of primary endosymbiosis is itself engulfed and retained by another eukaryotic cell o Engulfed cell becomes an endosymbiont Theory of Endosymbiosis

Evidence of Endosymbiosis 1. All eukaryotes have mitochondria or had them in the past 2. Mitochondria and chloroplasts contain DNA but lack nucleus 3. Mitochondria and chloroplasts contain their own ribosomes 4. Mitochondria and chloroplasts are able to self replicate by binary fission 5. Mitochondria and chloroplasts move freely within the cell

Primary and Secondary Endosymbiosis

Lineages of Prostists Flagellated Protozoans Alveolates Stramenopiles Red Algae Green Algae Amoebozoans

Flagellated Protozoans Single-celled organisms o lack a cell wall o one or more flagella o pellicle layer of protein under plasma membrane (shape) Reproduce asexually - binary fission Different types of flagellated protozoans: o Diplomonads o Parabasalids o Kinetoplastids o Euglenoids o Radiolarians o Foraminiferans Giardia lamblia

Alveolates Characterized by membrane bound sacs (aveoli) under the plasma membrane. o The function of the aveoli are unknown. Some hypothesis they help to stabilize the cell's surface or regulate the cell's water and ion content Includes flagellates (dinoflagellates), parasites (apicomplexans) and cilla motive protists (ciliates). Plasmodium vivax

Stramenopiles Stramenopiles contains o several groups of heterotrophs o some groups of algae shared characteristic: flagellum- hairlike projections that help with motion and feeling most have both a hairy and smooth flagellum o always paired together o 2 flagella=motile reproductive cells Synura petersenii

Red Algae red color derived from accessory pigment phycobili o allows absorption of blue and green light, which penetrate farther into water most abundant type of large algae in tropical oceans also found in freshwater and on land mostly multicellular diverse life cycles o often alternation of generations o no flagellated life stage Bonnemaisonia hamifera

Green Algae aquatic autotrophs chloroplasts similar to those of plants contains two groups: o chlorophytes  most live in freshwater, some in marine environments  simplest chlorophytes are biflagellated, unicellular  more complex/larger chlorophytes evolve through:  formation of colonies  repeated nucleic division without cytokinesis  formation of true multicellular forms- cell division and differentiation  complex life cycles  sexual and asexual reproductive stages  most reproduce sexually o charophyceans  most closely related to land plants Chlamydomonas nivalis

Amoebozoans characterized by lobe-shaped pseudopodia 3 types: o Gymnamoebas  heterotrophs o Entamoebas  parasites o Slime Molds  produce fruiting bodies for spore dispersal  Plasmodial Slime Molds  plasmodium life stage  unicellular, many diploid nuclei  Cellular Slime Molds  generally, cells function individually  lack of food- cells group, function as unit Physarum polycephalum

Works Cited phalum.jpg png h223.jpg Campbell/Reece 7th Edition Biology