Chapter 22 “Protists” – The Simplest Eukaryotes
Domain Eukarya
Kingdom Protista
Protistans
☺ Organisms may be algae like, animal like, or fungus like
☺ Unicellular or multicellular
☺ The earliest, structurally simple eukaryotes
☺ Have a nucleus, large ribosome, mitochondria, endoplasmic reticulum, Golgi
bodies
☺ Chromosomes consist of DNA molecule closely associated with many histones
and other proteins
☺ 9 + 2 array of microtubules in cilia and flagella
☺ Many species contain chloroplasts
☺ Divide by mitosis, meiosis or both
Parabasalids and Diplomonads
☺ Earliest single cell eukaryotes
☺ Heterotrophic flagellates
☺ Live in oxygen poor or anaerobic habitats
☺ Have few mitochondria or none
☺ Parabasalids
☺ Ex: Trichonympha campanula
☺ Flagellated cell is a cellulose-digesting symbiont in the gut of termites and
wood roaches
☺ Ex: Trichomonas vaginalis
☺ A parasite that attaches to the lining in the vagina or male reproductive tract
☺ Diplomonads
☺ Have 3 flagella at their anterior end and one at the trailing end
☺ Ex: Giardia lamblia
☺ No lysosomes, Golgi bodies, or mitochondria
☺ Intestinal parasite
☺ Cramps and diarrhea
☺ In areas of poor water quality and sewage treatment
Algae like Members of Protista
☺ Obtain energy by photosynthesis
☺ All have chlorophyll a and some other pigment molecules
☺ Euglenoids
☺ Live in freshwater and marine habitat
☺ Most are photoautotrophs and the rest are heterotrophs
☺ Obtain energy from photosynthesis
☺
☺
☺
☺
☺ Has chlorophyll a
☺ 1-3 flagellas
☺ Pellicles – this protein strips for cell wall
☺ Some have eyespot for phototaxis – move in response to light
Dinoflagellates
☺ Most are single photosynthetic cells that are major producers in marine
phytoplankton
☺ Have 2 flagella
☺ Few are symbionts with corals
☺ Some bioluminescent types make warm seawater shimmer at night
☺ Red Tides – form near coasts when certain species undergo blooms which turn
the water rusted or brown
☺ Few species produce toxins that kill fish and other animals
☺ Can cause brain damage when people eat seafood tainted with these toxins
Chrysophytes
☺ Free-living photoautotrophs and some heterotrophs
☺ Mostly single-celled
☺ Contain chlorophylls a, c1, c2
☺ Golden Algae
☺ Chlorophylls of cells are masked by a golden-brown carotenoid, fucoxanthin
☺ Yellow-Green Algae
☺ Common chrysophytes in aquatic habitats
☺ Most are motile, but have flagellated gametes
☺ Diatoms
☺ Have silica “shell” of two perforated with overlap it like a pill box
☺ Finely crushed shells of the extinct species of these cells accumulated at the
bottom of lakes and seas
☺ A lot of sediments we quarry for insulation, abrasives, and filters contain
these deposits
☺ Coccolithophores
☺ Single-celled photosynthesizers of marine habitats especially in tropics
☺ Dimethyl sulfide – a byproduct of these cells is noxious enough to make
migratory fishes deviate from normal routes
Red Algae
☺ Multicellular
☺ Most abundant in warm currents and tropical seas
☺ Some contribute to the formation of coral reefs and banks
☺ Different species appear red, green, purple, or nearly black, depending on which
accessory pigments mask chlorophyll a
Brown Algae
☺ Multicellular
☺ Thrive in cool or temperate water
☺ Species appear olive-green, golden or dark brown
☺ Range from microscopic to giant kelps, twenty to thirty meters long
☺ Giant kelps are the most complex protistans
☺ Giant kelp beds function as productive ecosystems (giant forests)
☺ Green Algae
☺ Have both chlorophyll a and b
☺ All are photosynthetic
☺ Structurally and biochemically most like plants and may be their closest relatives
☺ Store carbohydrates such as starch grains inside their chloroplasts
☺ Also grows at the ocean surface, in marine sediments, just below the surface of
soil, and on rocks, tree bark, other organisms and snow
Protozoa or Animal Like
☺ Heterotrophic
☺ Consume either living cells or dead organic matter
☺ Parasitic
☺ Foraminiferans
☺ Shells made of calcium carbonate
☺ Pseudopodia
☺ Single celled heterotrophs
☺ Radiolarian
☺ Outer perforated shell made of silica
☺ Live in deep ocean
☺ Ciliates
☺ Numerous cilia
☺ 65% are free living and motile
☺ Predator or symbionts some parasitic
☺ Contractile Vacuoles – organelle that takes up excess water in cell body and
contracts to expel water through a pore
☺ Ex: Paramecium
☺ Apicomplexa
☺ Parasitic protistans
☺ Cause serious human diseases
☺ No physical means of motility
☺ Many species alternate between reproductive modes in response to
environmental conditions
☺ Most commonly asexual reproduction is by binary fission
☺ Ex: Cryptosporidiosis – a water borne disease
☺ Ex: Pneumocystis carinii – lives in human lungs and many domestic and wild
animals. Causes a deadly form of pneumonia in two-thirds of all AIDS cases.
Untreated patients die from asphyxia, they stop breathing
☺ Ex: Toxoplasma – uses domestic and wild cats as host
Fungus Like
☺ Resemble fungus because they form either filaments or spore-bearing bodies
☺ Water Molds (Oomycota)
☺ Might be distantly related to yellow-green and brown algae
☺ Most of the 580 known types are key saprobic decomposers in aquatic habitats
☺ Many are free-living species that get nutrients from plant debris in ponds, lakes,
and streams
☺ Others live inside necrotic tissues of living plants
☺ Most water molds produce an extensive mycelium
☺ Reproduce asexually, by way of flagellates, asexual spores
☺ Some of the hyphae differentiate into gamete-producing structures
☺ Antheridium – produces male gametes
☺ Oogonium – produces female gametes
☺ At fertilization, a male and female gamete fuse to form a diploid zygote which is
surrounded into by a hard shell and grows into the soil
☺ Slime Molds (Acrasiomycota)
☺ Produce free-living, amoeba like cells during parts of the life cycle
☺ Groups includes cellular slime molds, and plasmodial slime molds
☺ Cells crawl on rotting plant parts such as decaying leaves and bark
☺ Like true amoebas, they are phagocytic predators, engulf bacteria and yeast,
spores and various other organic compounds
☺ Phagocytosis – cell surrounds and takes in solid particles
☺ When nutrients dwindle, many of the starving cells aggregate and form a slimy
mass. The mass may migrate to a new location where conditions favor growth
☺ Amoeba like cells develops into a few cell types that differentiate and form a
spore-bearing structure. After the spores are released, they germinate on warm,
damp surfaces. Each spore gives rise to one amoeba like cell
☺ Sexual reproduction, by gametes, also is common among slime molds
Chapter 22 “Protists” – The Simplest Eukaryotes
Domain Eukarya
Kingdom Protista
Protistans
☺ Organisms may be algae like, animal like, or fungus like
☺
☺ The earliest, structurally simple eukaryotes
☺ Have a nucleus, large ribosome, mitochondria, endoplasmic reticulum, Golgi
bodies
☺ Chromosomes consist of DNA molecule closely associated with many
_______________ and other proteins
☺ 9 + 2 array of microtubules in ____________ and ____________
☺ Many species contain _______________
☺
Parabasalids and Diplomonads
☺ Earliest single cell eukaryotes
☺
☺ Live in oxygen poor or anaerobic habitats
☺ Have few _______________ or none
☺ Parabasalids
☺ Ex: Trichonympha campanula
☺ Flagellated cell is a cellulose-digesting symbiont in the gut of termites and
wood roaches
☺ Ex: Trichomonas vaginalis
☺ A parasite that attaches to the lining in the vagina or male reproductive tract
☺ Diplomonads
☺ Have ____ flagella at their anterior end and ____ at the trailing end
☺ Ex: Giardia lamblia
☺ No lysosomes, Golgi bodies, or mitochondria
☺
☺
☺ In areas of poor water quality and sewage treatment
Algae like Members of Protista
☺ Obtain energy by ____________________
☺ All have chlorophyll a and some other pigment molecules
☺ Euglenoids
☺
☺ Most are photoautotrophs and the rest are heterotrophs
☺ Obtain energy from photosynthesis
☺ Has chlorophyll a
☺
☺ Pellicles –
☺ Some have eyespot for phototaxis –
☺ Dinoflagellates
☺ Most are single photosynthetic cells that are major producers in marine
phytoplankton
☺
☺ Few are symbionts with ____________
☺ Some bioluminescent types make warm seawater shimmer at night
☺ Red Tides –
☺ Few species produce toxins that kill fish and other animals
☺ Can cause brain damage when people eat seafood tainted with these toxins
☺ Chrysophytes
☺ Free-living photoautotrophs and some heterotrophs
☺
☺ Contain chlorophylls _____, _____, _____
☺ Golden Algae
☺ Chlorophylls of cells are masked by a golden-brown _______________,
fucoxanthin
☺ Yellow-Green Algae
☺ Common chrysophytes in _______________ habitats
☺ Most are motile, but have flagellated gametes
☺ Diatoms
☺ Have ____________ “shell” of two perforated with overlap it like a pill box
☺ Finely crushed shells of the extinct species of these cells accumulated at the
bottom of lakes and seas
☺ A lot of sediments we quarry for insulation, abrasives, and filters contain
these deposits
☺ Coccolithophores
☺ Single-celled photosynthesizers of marine habitats especially in tropics
☺ Dimethyl sulfide –
☺ Red Algae
☺
☺ Most abundant in warm currents and tropical seas
☺ Some contribute to the formation of __________ __________ and banks
☺ Different species appear red, green, purple, or nearly black, depending on which
accessory pigments mask chlorophyll a
☺ Brown Algae
☺
☺ Thrive in __________ or temperate water
☺ Species appear olive-green, golden or dark brown
☺ Range from microscopic to giant kelps, twenty to thirty meters long
☺ __________ __________ are the most complex protistans
☺ Giant kelp beds function as productive ecosystems (giant forests)
☺ Green Algae
☺ Have both chlorophyll _____ and _____
☺
☺ Structurally and biochemically most like ____________ and may be their closest
relatives
☺ Store carbohydrates such as starch grains inside their chloroplasts
☺ Also grows at the ocean surface, in marine sediments, just below the surface of
soil, and on rocks, tree bark, other organisms and snow
Protozoa or Animal Like
☺
☺ Consume either living cells or dead organic matter
☺
☺ Foraminiferans
☺
☺
☺ Single celled heterotrophs
☺ Radiolarian
☺ Outer perforated shell made of ____________
☺
☺ Ciliates
☺ Numerous cilia
☺ _______ are free living and motile
☺ Predator or symbionts some parasitic
☺ Contractile Vacuoles –
☺ Ex:
☺ Apicomplexa
☺
☺ Cause serious human diseases
☺ No physical means of ____________
☺ Many species alternate between reproductive modes in response to
environmental conditions
☺ Most commonly asexual reproduction is by ____________ ____________
☺ Ex: Cryptosporidiosis –
☺ Ex: Pneumocystis carinii – lives in human lungs and many domestic and wild
animals. Causes a deadly form of pneumonia in two-thirds of all AIDS cases.
Untreated patients die from asphyxia, they stop breathing
☺ Ex: Toxoplasma –
Fungus Like
☺ Resemble fungus because they form either filaments or spore-bearing bodies
☺ Water Molds (Oomycota)
☺ Might be distantly related to ____________________ and _____________ algae
☺ Most of the _______ known types are key saprobic decomposers in aquatic
habitats
☺ Many are free-living species that get nutrients from plant debris in ponds, lakes,
and streams
☺
☺ Most water molds produce an extensive ____________
☺ Reproduce asexually, by way of flagellates, asexual spores
☺ Some of the hyphae differentiate into gamete-producing structures
☺ Antheridium –
☺ Oogonium –
☺ At fertilization, a male and female gamete fuse to form a diploid zygote which is
surrounded into by a hard shell and grows into the soil
☺ Slime Molds (Acrasiomycota)
☺ Produce free-living, amoeba like cells during parts of the life cycle
☺ Groups includes cellular slime molds, and plasmodial slime molds
☺ Cells crawl on rotting plant parts such as decaying leaves and bark
☺ Like true amoebas, they are _______________ predators, engulf bacteria and
yeast, spores and various other organic compounds
☺ Phagocytosis –
☺ When nutrients dwindle, many of the starving cells aggregate and form a slimy
mass. The mass may migrate to a new location where conditions favor growth
☺ Amoeba like cells develops into a few cell types that differentiate and form a
spore-bearing structure. After the spores are released, they germinate on warm,
damp surfaces. Each spore gives rise to one amoeba like cell
☺