THE ORIGINS OF EUKARYOTIC DIVERSTIY

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CHAPTER 28

• THE ORIGINS OF EUKARYOTIC DIVERSTIY

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• PROTISTS
• THE MOST DIVERSE GROUP OF EUKARYOTES
• MOST ARE UNICELLULAR
• CONSIDERED THE SIMPLEST OF THE EUKARYOTES
• QUITE COMPLEX AT THE CELLULAR LEVEL
• MOST PROTISTS ARE ABLE TO CARRY OUT ALL LIFE
  FUNCTIONS

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• NUTRITIONALLY DIVERSE
• PROTOZOA INGETIVE (ANIMAL LIKE)
• FUNGUSLIKE PROTISTS ABSORBTIVE
• ALGAE PHOTOSYNTHETIC (PLANTLIKE)
• MIXOTROPH BOTH HETEROTROPHIC AS WELL AS
  PHOTOSYNTHETIC

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• MOTILITY
• CILIA _at_ FLAGELLA WHICH ARE EXTENSIONS OF THE
  CYTOPLASM (UNLIKE PROKARYOTES WHERE IT EXTENDS
  FROM THE CELL SURFACE)
• PSEUDOPODEA

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• REPRODUCTION
• MOST ARE ASEXUAL, ALTHOUGH IT IS QUITE VARIED
• MOST ARE MITOTIC
• SOME MEIOSIS SEXUAL SYNGAMY (UNION OF GAMETES
• LIFE CYCLES USUALLY HAVE A PERIOD OF CYST
  FORMATION (PROTECTION)

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• PROTISTS ARE FOUND ANYWHERE THERE IS WATER
• IMPORTANT CONSTITUANTS OF PLANKTON, WHICH ARE
  COMMUNITIES OF ORGANISMS THAT ARE CRITICAL IN THE
  FOOD CHAIN IN MARINE AND FRESHWATER
• PHTYOPLANKTON PHOTOSYNTHETIC PROTISTS,
  RESPONSIBLE FOR ½ OF THE PHOTOSYNTHESIS ON THE
  PLANET

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• ENDOSYMBIOTIC THEORY
• THE HYPOTHESIS OF THE EVOLUTION OF EUKARYOTES
  FROM PROKARYOTES
• ENDOSYMBIOSIS A CELL THAT LIVES WITHIN ANOTHER
  CELL.
• MITOCHONDRIA _at_ CHLOROPLASTS WERE FORMERLY SMALL
  PROKARYOTES LIVING SYMBIOTICALLY WITHIN A LARGER
  CELL
• THE RESULT WAS THE FORMATION OF MITOCHONDRIA AND
  CHLOROPLASTS
• SUPPORTING THIS THEORY IS THAT BOTH CONTAIN THEIR
  OWN DNA

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• 1969 ROBERT WHITAKER
• POPULARIZED THE 5 KINGDOM SYSTEM AND ASSIGNED
  UNICELLULAR EUKARYOTES THEIR OWN KINGDOM PROTISTA
• THE CURRENT 8 KINGDOM CLASSIFICATION SUGGESTS 3
  PROTIST KINGDOMS
• ARCHAZOA
• PROTISTA
• CHROMISTA

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• ARCHAZOA
• LACK MITOCHONDRIA
• LACK PLASTIDS
• CLOSE RELATIONSHIP WITH PROKARYOTIC m-RNA
• MANY ARE PARASITIC
• SUBGROUP DIPLOMONADS (PARASITES)
• GIARDIA INTESTINALIS
• FLAGELLATED
• 2 NUCLEI
• NO MITOCHONDRIA
• NO PLASTIDS
• FOUND IN WATER CONTAMINATED WITH HUMAN FECES

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• EUGLENOZOANS
• CANDIDATE KINGDOM
• EUGLENOIDS FLAGELLATED, MIXOTROPH OR
  HETEROTROPHIC
• EUGLENAS

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• KINETOPLASTIDS
• SINGLE LARGE MITOCHONDRIA
• ASSOCIATED WITH THE ORGANELLE KNOWN AS THE
  KINETOPLAST, WHICH HOUSE DNA EXTRACELLULARLY
• SYMBIOTIC PATHOGENS TO A HOST
• Ex. TRYPANOSOMA (Tsetse FLY)
• CAUSE THE DISEASE AFRICAN SLEEPING SICKNESS

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• ALVEOLATA - PHOTOSYNTHETIC FLAGELLATES
• DINOGLAGELLATES
• DINO (WHIRLING)
• COMPONENTS OF PHYTOPLANKTON
• MAY CAUSE RED TIDE DUE TO THE HIGH CONCENTRATION
  OF THE PIGMENT XANTHOPYLL
• PAIR OF FLAGELLA
• PFEISTERIA PISCICIDA DANGEROUS, CARNIVOROUS TO
  FISH,
• THEY ALSO MAY LIVE SYMBIOTICALLY WITH CNIDARIANS
  AND BUILD CORAL REEFS

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• APICOMPLEXANS
• FORMERLY SPOROZOANS
• ANIMAL PARASITES
• RELEASE TINY INFECTOUS CELLS KNOWN AS SPOROZOITES
• PLASMODIUM AN APICOMPLEXAN THAT CAUSES MALARIA,
  WHICH IS CARRIED ON THE MOSQUITO

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• CILIATES (CILIOPHORANS)
• CILIA ARE FOR MOTION AND FEEDING
• LIVE AS INDIVIDUAL CELLS IN FRESH WATER
• REPRODUCE BY BINARY FISSION
• CONJUGATION AND GENETIC RECOMBINATION OCCUR IN
  PARAMECIUM
• THEY HAVE 2 TYPES OF NUCLEI
• MICRONUCLEI FOR GENETIC RECOMBINATION
• MACRONUCLEI CONTROL CELLULAR FUNCTIONS

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• THERE ARE 3 GROUPS OF PROTISTS THAT MOVE VIA
  PSEUDOPODS
• RHIZOPODS
• ACTINOPODS
• FORAMINIFERANS

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• RHIZOPODS (ROOT LIKE FEET)
• AMOEBAS
• UNICELLULAR
• PSEUDOPOD MOVEMENT
• MOST ARE FREE LIVING, EXCEPT ENTAMOEBA
  HISTOLYTICA WHICH CAUSES AMEBIC DYSENTARY IN
  HUMANS. IT IS SPREAD BY DRINKING CONTAMINATED
  DRINKING WATER OR FOOD

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• MOST UNICELLULAR EUKARYOTES ARE HETEROTROPHIC AND
  WILL SEEK BACTERIA OR OTHER PROTISTS TO CONSUME.
  
• CERTAIN PROTISTS WILL CONSUME DEAD ORGANIC MATTER
  WHICH IS KNOWN AS DETRITIS

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• ACTINOPODS
• COMPONENTS OF PLANKTON
• FEED WITH AXOPODIA A SLENDER PSEUDOPOD
• DIE AND SETTLE TO THE BOTTOM OF THE SEA
• MICROTUBULES REINFORCE AN INTERNAL SKELETON
• Ex. HELIOZOANS FRESH WATER, GLASSY APPEARANCE
  (SKELETON IS MADE UP OF SILICEOUS MATERIAL)
• RADIOLARIANS MARINE, WHEN DEAD SETTLE TO THE
  OCEAN FLOOR

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• FORAMINIFERANS (FORAMS)
• ALL ARE MARINE
• POROUS SHELL
• COMPONENTS OF SEDIMENTARY ROCK
• FOUND IN ROCKS AND ALGAE
• MAY BE FOUND IN PLANKTON AS WELL
• FOSSILIZED SHELLS ARE USED TO DATE AGES OF
  SEDIMENTARY ROCK

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• SLIME MOLDS
• SIMILAR TO FUNGI
• CLOSER TO AMOEBAS
• DECOMPOSERS

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• PLASMODIAL SLIME MOLD
• MYXOMYCOTA
• HETEROTROPHIC
• BRIGHT COLORS, ORANGE _at_ YELLOW
• PLAMODIUM STAGE IS THE FEEDING STAGE, WHICH IS AN
  AMOEBOID MASS OF CELLS

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• CELLULAR SLIME MOLD
• ACRASIOMYCOTA
• HAPLOID ORGANISM, ONLY THE ZYGOTE IS DIPLOID
• NO FLAGELLATED STAGE
• REMAIN AS SEPERATE CELLS UNLIKE PLASMODIAL SLIME
  MOLD DURING FEEDING
• FRUITING BODIES THAT FUNCTION IN ASEXUAL
  REPRODUCTION

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• STRAMENOPILA (CHROMISTA)
• DIATOMS
• GOLDEN ALGAE
• BROWN ALGAE
• WATER MOLDS, WHITE RUSTS DOWNY MILDEWS (OOMYCOTES)

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• DIATOMS (BACILLARIOPHYTA)
• YELLOW OR BROWN
• GLASSLIKE SHELLS (2 HALVES) SHELL SHAPE AND PORE
  PATTERN ARE USED TO CLASSIFY DIATOMS
• MAJOR COMPONENT OF PLANKTON

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• GOLDEN ALGAE (CHRYSOPHYTA)
• CHRYSO GOLDEN
• BIFLAGELLATED CELLS
• FOUND IN PLANKTON
• SOME CAN BE MIXOTROPHIC
• MOST ARE UNCELLULAR
• MAY BE COLONIAL (DINOBRYON)

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• WATER MOLDS (OOMYCOTA)
• HETEROTROPHIC
• LACK CHLOROPLASTS
• MOST ARE DECOMPOSERS FOUND IN WATER
• 1870S CAUSED THE IRISH POTATO FAMINE

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• BROWN ALGAE (PHAEOPHYTA)
• LARGEST AND MOST COMPLEX
• MULTICELLULAR
• MOST ARE MARINE
• SEAWEEDS AND LARGE MARINE ALGAE
• ANALOGOUS TO PLANTS (NOT HOMOLOGOUS)

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• STRUCTURE OF SEAWEED
• THALLUS BODY, PLANTLIKE BUT NO TRUE ROOTS STEMS
  OR LEAVES
• HOLDFAST ROOT LIKE, ANCHORS ALGAE
• STIPE STEM LIKE, SUPPORT THE BLADES
• BLADES LEAFLIKE PROVIDE THE PHOTOSYNTHETIC
  SURFACE
• FOUND ALONG COASTAL WATERS

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• KELP (GIANT SEAWEED)
• STIPES MAY BE EXTREMELY LONG (60 METERS)
• THALLI OF SOME SEAWEEKS ADAPT TO THE OCEAN BY
  FORMING A POLYSACCHARIDE COAT WHICH CREATES A
  SLIMEY FEEL BUT SERVES AS PROTECTION FROM THE
  ENVIRONMENT
• MAJOR SOURCE OF FOOD WORLD WIDE
• GEL FORMING SUBSTANCES FROM SEAWEED
• ALGIN-FROM BROWN ALGAE
• AGAR RED ALGAE, USED FOR THICKENERS IN
  PROCESSED FOOD AS WELL AS RESEARCH

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• LIFE CYCLE CONSISTS OF A COMPLEX COMPONENT WHICH
  IS
• ALTERATION OF GENERATIONS
• THIS CONSISTS OF HAPLOID AND DIPLOID FORMS

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• LAMINERARIA LIFE CYCLE
• SPOROPHYTE DIPLOID INDIVIDUAL WHICH PRODUCES
  REPRODUCTIVE CELLS
• GAMETOPHYTE HAPLOID INDIVIDUAL WHICH WILL
  PRODUCE GAMETES
• THESE TWO ALTERNATE, OR TAKE TURNS REPRODUCING
  ONE ANOTHER
• HETEROMORPHIC A SPOROPHYTE _at_ GAMETOPHYTE ARE
  STRUCTURALLY DIFFERENT
• ISOMORPHIC LOOK THE SAME, JUST A DIFFERENT
  CHROMOSOME NUMBER

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• RED ALGAE (RHODOPHYTA)
• NO FLAGELLATED STAGES, FLAGELLA SEEM TO HAVE BEEN
  LOST THROUGH EVOLUTION
• CONTAIN PHYCOCRYTHRIN A RED PIGMENT
• FOUND IN WARM COASTAL WATERS
• MOST, NOT ALL ARE RED

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• GREEN ALGAE (CHLOROPHYTA)
• CLOSELY RELATED TO PLANTS
• 7,000 SPECIES
• MOSTLY FRESHWATER, SOME MARINE
• CELL WALLS MADE OF CELLULOSE
• CONTAIN CHLOROPLASTS
• PHOTOSYNTHETIC
• LICHENS A SYMBIOTIC RELATIONSHIP BETWEEN
  CHLOROPHYTES AND FUNGI

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• CHLAMYDOMONAS
• SIMPLEST CHLOROPHYTE
• BIFLAGELLATED UNICELLULAR
• LIFE CYCLE INCLUDES SEXUAL _at_ ASEXUAL STAGES
• ALL STAGES ARE HAPLOID EXCEPT FOR THE ZYGOTE
  STAGE
• GAMETES APPEAR SIMILAR AND FUSION IS KNOWN AS
  ISOGAMY
• ISOGAMY MARRIAGE OF EQUALS
• ANISOGAMY MALE _at_ FEMALE GAMETES DIFFER IN SIZE
• OOGAMY FLAGELLATED SPERM _at_ NON MOTILE EGG

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• DIFFERENT EVOLUTIONARY TRENDS HAVE PRODUCED
  VARIOUS TYPES OF CHLOROPHYTES
• 1. VOLVOX COLONIAL COLLECTION OF CELLS
• 2. CAULERPA CONTINUAL NUCLEAR DIVISION WITH
  NO CYTOPLASMIC DIVISION
• 3. ULVA TRUE MULTICELLULAR FORMS

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