PROTISTS
PROTISTS
COMMON EXAMPLES:Amoeba, paramecium, euglena, volvox, plasmodium
EUKARYOTICHave a nuclear membrane
VERY DIVERSE GROUPmost are unicellular, microscopic, aerobicSome are autotrophic, heterotrophic, sexual, asexual
PROTISTS
ENDOSYMBIONT THEORYEarly 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
PROTISTS
EXCRETION AND OSMOREGULATION
Water balance = osmoregulation
Done by contractile vacuole
Wastes removed by diffusion
RESPIRATIONCarbon dioxide and oxygen diffuse in and out
PROTISTS
REPRODUCTIONAsexual
Mitosis and cytokinesis
Budding – similar to mitosis except daughter cell is smaller than parent
Schizogony – nucleus divides many times and cytoplasm divides to form many daughter cells as there are nuclei
PROTISTS
SEXUALLYMeiosis – special nuclear division to reduce chromosome number to haploid
Union of gametes = diploid zygote
Syngamy – fertilization between two individuals
Autogamy – two gametes fuse within one organism
Parthenogenesis – development of organism from gamete without fertilization
Conjugation – exchange of nuclear material between two individuals
PROTISTS
DOMAIN EUKARYOTA
KINGDOM PROTISTAAny eukaryote that is not classified as a fungus, plant, or animal is a PROTIST
PROTISTS
ANIMAL LIKE PROTISTS = PROTOZOA
Classified by method of movement
PLANT LIKE PROTISTS = ALGAEClassified by pigment color
FUNGUS LIKE PROTISTS = MOLDSClassified by body form
PROTISTS
PROTIST CLASSFICATIONSeparated by feeding habits (nutrition)
AutotrophicAble to make own food
Photosynthetic – 30-40% of all photosynthesis worldwide is done by algae
HeterotrophicMust eat other material
Unicellular
May be predators, decomposers, or parasites
PROTISTS
PROTOZOAHeterotrophic
Unicellular
4 groups
Sarcodinians
Zooflagellates
Ciliophorans
Sporozoans
PROTISTS
PHYLUM SARCODINAAquatic, clear cytoplasm, irregular shape
Move by extending lobes of their cytoplasm
Pseudopods (false feet)
Plasmolemma – elastic cell membrane
Cytoplasm is divided into ectoplasm and endoplasm
Nucleus, contractile vacuole, food vacuole
Example: Amoeba proteus
PROTIST
PROTIST
LABEL THIS AMEOBA
PROTISTS
PHYLUM ZOOMASTIGINAOften called flagellates because they move using flagella
Absorb food by diffusion through cell membrane
Live off of dead or decaying organic matter or some are parasites
Trichonympha lives in the gut of termites (helps termite digest wood)
Trypanosoma – parasite of humans in Africa
PROTISTS
PROTISTS
PHYLUM CILIOPHORACiliates – found in fresh and salt water; usually free-living, most are larger than other protozoaPellicle, cilia, ectoplasm, endoplasm, food vacuole, contractile vacuoleMicronucleus (exchanged during conjugation)Macronucleus (controls daily functions)
PROTISTS
TRICHOCYSTS – spindle shaped alternating between bases of cilia; used as anchor and to paralyze preyOral groove – shallow furrow on one side of cell used to gather foodLocomotion – cilia; avoiding reaction contact with unfavorable conditions and will move away
Reacts to contact, temperature, gravity, water currents, electric currents, acidity and other chemicals
PROTISTS
ReproductionMitosis every 6-12 hours
Conjugation – become sticky and adhere to each other at oral groove and exchange nuclear material
Example = paramecium
PROTIST
PROTISTS
PHYLUM SPOROZOAMembers cannot moveReproduce by producing sporesAll endoparasitesHave apical complexes (structures that aid in penetration of host cells or tissues)Example: Plasmodium – causes malaria; carried by vector (female Anopheles mosquito)
PROTISTS
PROTISTS
PLANT LIKE PROTISTSMost perform photosynthesis
Contain chlorophyll in chloroplast and possibly other pigments
Divided into groups by pigment colorPHYLUM EUGLENOPHYTA
PHYLUM DINOFLAGELLATA
PHYLUM HETEROKONTOPHYTA
PHYLUM CHLOROPHYTA
PROTIST
PHYLUM EUGLENOPHYTAUsually free-living (not a parasite)Pellicle – covering membrane; maintains shapeEctoplasm, endoplasmCell mouth, gullet, reservoir (holds flagella), contractile vacuole, food vacuoleStigma (eyespot) - light sensitiveNucleus, chloroplasts
PROTISTS
Movement toward light using flagella; flagella pulls cell; euglenoid movement expansion and contractions of entire cell
Nutrition – can capture food; can absorb nutrients from water or carry on photosynthesis
Reproduction – mitosis; form cyst during harsh times
Example: euglena; volvox
PROTISTS
PROTISTS
PHYLUM CHLOROPHYTA - GREEN ALGAE
Contain chlorophyll b is their main type (which is very similar to land plants)
Some reproduce sexually
Examples: desmids, spirogyra
Most live in fresh water or moist soil
Many live in symbiotic relationshipsLichen – organism composed of an algae and a fungi living together as one
PROTISTS
PROTISTS
PROTISTS
PROTISTS
PHYLUM HETEROKONTOPHYTARed algae, brown algae, golden algae
RED ALGAEGrow in warm salt water habitats – toward surface or deep water
Perform photosynthesis
Example: Red moss
PROTISTS
BROWN ALGAEMulticellular and live in cool salt water habitats
Includes giant kelps
Have an alternation of generations life cycle (means that part of life is spent reproducing asexually and part is spent reproducing sexually)
PROTISTS
Used to make a variety of productsAs a thickening agent in puddings, ice creamUsed as food for animals (processed)
PROTISTS
GOLDEN ALGAE –Some species are colorless, but the vast majority are photosynthetic.
particularly important in lakes, where they may be the primary source of food for zooplankton.
not considered truly autotrophic because nearly all become heterotrophic in the absence of adequate light, or in the presence of plentiful dissolved food.
EXAMPLES - DIATOMS
PROTISTS
PHYLUM DINOFLAGELLATA (termed Pyrrophyta in your book)
Nearly all have flagella
Most grow in salt water
Most are free-living (meaning they are not parasites); some have symbiotic relationships with other organisms
When agitated undergo reaction that produces light bioluminescent
PROTISTS
DINOFLAGELLATE
PROTISTS
Cause the red tideSeveral microscopic marine algae are notoriously poisonous to hapless humans who consume them in shellfish. some species are poisonous to animals which feed upon them directly or indirectly. Some of the toxins these species produce are seriously toxic. Often, the algae themselves are unaffected, as are the filter feeders, especially shellfish, for whom micro-algae are the principal diet. However, to carnivores further up the food chain, including humans, these toxins are potentially FATAL.
PROTISTS
PROTISTS
FUNGUS-LIKE PROTISTS (MOLDS)CHARACTERISTICS
MOST ARE SMALL AND LIVE IN DAMP PLACESPROTISTS THAT ACT AS DECOMPOSERS ARE CALLED MOLDS
DIVIDED INTO 3 GROUPSPLASMODIAL SLIME MOLDSCELLULAR SLIME MOLDSWATER MOLDS
PROTISTS
PLASMODIAL SLIME MOLDSCan weigh as much as 50 grams and be as large as a human hand (one cell!)
Single cell with many nuclei
In unfavorable conditions
Moves somewhere else
Creates a fruiting body
Myxomycota - plasmodium
PROTISTS
CELLULAR SLIME MOLDSALTERNATES BETWEEN A SPORE PRODUCING FRUITING BODY FORM AND AN AMEBALIKE FEEDING FORM
SINGLE CELLS UNITE TO FORM ONE LARGE MASS (PSEUDOPLASMODIUM) WHEN TIMES ARE HARSH
The phyla of slime molds:
PROTISTS
WATER MOLDSDECOMPOSERS IN FRESHWATER ECOSYSTEMS
SOME ARE PARASITIC
PROTISTS
IMPORTANCE OF PROTISTSECOLOGICAL ROLES
Provide an essential food base in aquatic food chains
Carry out more than 30-40% of Earth’s photosynthesis
Protozoans help keep the number of bacteria in check