Protists Biology Chapter 20

20-1: The Kingdom Protista Protista: Greek: “the very first”

What is a Protist? Most diverse kingdom Protist may be: Unicellular or multicellular Microscopic or very large Autotrophic or heterotrophic Protists are eukaryotes that are not members of the kingdom Plantae, Animalia, or Fungi There is no “typical protist”

PROTISTS ENDOSYMBIONT THEORY Early eukaryotes developed symbiotic relationships with prokaryotic cells Prokaryotic cells lived inside eukaryotic cells Over time, the smaller prokaryotic cells evolved with the eukaryotic cells to become mitochondria and chloroplasts

Evolution of First Eukaryote(s) Forces leading to eukaryote Increases in size Increases in complexity Mechanisms Infolding of cell membrane Serial endosymbiosis of membrane-bound organelles Best guess for mechanism based on observations to date Mitochondria and chloroplasts are about the size of prokaryotes Chemistry of them is more similar to related prokaryotes than to the chemistry in rest of cytosol Mitochondria and chloroplasts have their own genes, arranged in simple DNA loops like prokaryotes Endosymbiosis is a common occurrence among present day forms (among all kindoms) This took place way back in time, maybe as long ago as 1500 mya (early Proterozoic) Of course, it happened in the early ocean.

Classification of Protist 3 basic types based on how they obtain their nutrients Protozoa Animal-like All unicellular Plantlike Resemble plants because they are autotrophs Do not have roots, stems, and leaves Funguslike protist Resemble fungi because they decompose dead organisms

PROTIST CLASSFICATION Separated by feeding habits (nutrition) Autotrophic Able to make own food Photosynthetic – 30-40% of all photosynthesis worldwide is done by algae Heterotrophic Must eat other material Unicellular May be predators, decomposers, or parasites

PROTISTS ANIMAL LIKE PROTISTS = PROTOZOA PLANT LIKE PROTISTS = ALGAE Classified by method of movement PLANT LIKE PROTISTS = ALGAE Classified by pigment color FUNGUS LIKE PROTISTS = MOLDS Classified by body form

Watch video on Protists http://www.youtube.com/watch?v=-zsdYOgTbOk&feature=player_detailpage

20-2: Animal-like Protists: Protozoans Protozoan: “first animals”

What is a Protozoan? All are unicellular heterotrophs Feed on other organisms or dead matter Typically reproduce asexually but can reproduce sexually Grouped by method of movement (4) Zooflagellates: flagella Sarcodines pseudopods Ciliates: cilia Sporozoans :non-motile: do not move

tiny beating hair-like structures Protozoans classified by the 4 ways they move: 1) Cilia - tiny beating hair-like structures Coordinated movement between individual cilia 2) Flagellum(a) - whip-like tail(s) Back and forth wave motion

classified by the 4 ways they move: Protozoans classified by the 4 ways they move: 3) Pseudopodia - projection of cytoplasm that sticks out like a foot (“false foot”) http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/wimsmall/flagdr.html http://micro.magnet.fsu.edu/moviegallery/pondscum/protozoa/amoeba/index.html 4) Sessile - No locomotion (_________) movement

Phylum Zoomastigina Often called flagellates because they move using 1 or 2 flagella Absorb food by diffusion through cell membrane Live off of dead or decaying organic matter or some are parasites Reproduce asexually by mitosis and cytokinesis Sexually by meiosis

symbiotic relationship: Trichonympha Trichonympha lives in the gut of termites and helps termite digest cellulose in wood. symbiotic relationship: MUTUALISM

One flagellate, Trypanosoma, causes African Sleeping Sickness 1) Infected Tsetse fly bites human, 2) Trypanosoma enters blood stream, causes lethargy, swollen lymph nodes, 3) effects central nervous system and causes death if not treated. Every day, about 100 people die from the disease. Every day, about 100 people die from the disease.

Trypanosoma

Giardia Giardiasis: transmission by contaminated water Causes diarrea and vomiting ALWAYS BOIL WATER WHEN CAMPING: boiling water will kill giardia

PHYLUM SARCODINA Live in moist places (most live in saltwater) irregular shape Amoeboid movement - move by pushing out extensions of cytoplasm called pseudopodia (false foot) Plasmolemma – elastic cell membrane NO cell wall Cytoplasm is divided into ectoplasm and endoplasm Nucleus, contractile vacuole, food vacuole During extreme conditions some form cysts Example: Amoeba proteus

Amoeba proteus: quiz Endoplasm Ectoplasm Know all structures and their functions!

Ameoboid movement Click on the link below to watch ameoboid movement http://www.youtube.com/watch?v=PsYpngBG394&feature=player_detailpage

Amoeba proteus feeding sequence psuedopodia surround and engulf food particle process called phagocytosis

Watch video of amoeba feeding http://www.youtube.com/watch?v=W6rnhiMxtKU&feature=player_detailpage

Foraminferans and Helizoans Shelled Sarcodines

Ciliates Phylum Ciliophora Live in any aquatic habitat Use cilia for feeding and movement Examples Paramecium Typically undergoes asexually but can undergo conjugation (exchange of genetic material)

PHYLUM CILIOPHORA Ciliates – found in fresh and salt water; usually free-living, most are larger than other protozoa Pellicle, cilia, ectoplasm, endoplasm, food vacuole, contractile vacuole Micronucleus (exchanged during conjugation) Macronucleus (controls daily functions)

PHYLUM CILIOPHORA TRICHOCYSTS – spindle shaped alternating between bases of cilia; used as anchor and to paralyze prey Oral groove – shallow furrow on one side of cell used to gather food Locomotion – cilia; avoiding reaction  contact with unfavorable conditions and will move away Reacts to contact, temperature, gravity, water currents, electric currents, acidity and other chemicals

Paramecium caudatum Anal pore Know each term in the diagram

Reproduction Example = paramecium Mitosis every 6-12 hours Conjugation – become sticky and adhere to each other at oral groove and exchange nuclear material Example = paramecium

Quiz yourself 4 3 1 5 2 6 9 7 10 8

Unicellular, slipper-shaped move by coordinated beating of many cilia Paramecium movement Unicellular, slipper-shaped move by coordinated beating of many cilia http://www.micrographia.com/specbiol/protis/homamoeb/amoe0100.htmhttp://www.micrographia.com/specbiol/protis/homamoeb/amoe0100.htm http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookDiversity_3.html

Watch a paramecium feeding http://www.youtube.com/watch?feature=player_detailpage&v=zS0f82ZJtvk

Paramecium: food to waste pathway http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookDiversity_3.html

Undulating membrane in groove (ciliary) Food vacuoles Oral groove on surface Macronucleus w/ micronuclei behind Cilia Contractile vacuoles Food particles Site of cell “anus”

Paramecium reproduction 1. Binary fission (________) asexual N = nucleus F = Fission plane http://www.lima.ohio-state.edu/biology/biodiv/webproto.htm http://www.lima.ohio-state.edu/biology/biodiv/proto/parafis.jpg

Paramecium reproduction 2. Conjugation (________) sexual Form structure called conjugation tube to exchange genetic material Micronucleus is exchanged http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20102/Bio%20102%20Laboratory/Protists/protists.htm http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20102/Bio%20102%20Laboratory/protists/paramecium_multimicronulleatum_conjugating_X_200.JPG

Watch a paramecium reproducing http://www.youtube.com/watch?v=K0ZP8VtxUZ0&feature=player_detailpage

Sporozoans Most produce spores All are parasites Found in blood or intestines Example Plasmodium Genus that causes malaria in humans Transmitted by female Anopheles mosquitoes More than 300-500 million people have malaria & 1.5-2.7 million die of malaria every year

Chloroquine: drug used to treat malaria BUT……..

Toxoplasma (not in book)

Cryptosporidium (not in book) Can be a problem in public splash areas