Chapter 20- Protists
Characteristics of Kingdom Protista
• eukaryotic cell type
• classified by mode of nutrition (how they
get their food)- ingest, photosynthetic, OR
decompose/parasites
• most diverse kingdom; “catch-all”
kingdom
• mostly unicellular; auto-or heterotrophic
3 major groups:
• animal-like (protozoans- all unicellular)
• plant-like (algae)
• fungal-like (“molds”)
I. Animal-like protists- aka PROTOZOANS
20-1
I. Animal-like protists- aka PROTOZOANS
A. zooflagellates- Phylum Zoomastiginaharmful or helpful; sleeping sickness;
termite guts to digest wood; mostly
asexual (mitosis/cytokinesis); some sexual
rep. where (gametes fuse)
Trypanosoma brucei
Trichonympha –
termite gut
Giardiacampers/
hikers
gambiense-African
sleeping sickness
Trichomonas vaginalis
B. Phylum Sarcodina -amoebas--pseudopodia
to move (amoeboid movement) and feed, no
cell wall, food vacuole, asexual reproduction
(mitosis/ cytokinesis); some parasitic
Entameoba –causes dysentery
C. Phylum Ciliophora -ciliates- -cilia for feeding and
locomotion, fresh/saltwater, Paramecium - (trichocysts,defense, micronucleus (all genes-repro.) and macronucleus
(most genes-daily needs), gullet, food vacuoles &
lysosomes,
anal pore, contractile
vacuole (pumps excess
water-homeostasis);
asexual rep./ but also a
sexual process called
conjugation
Conjugation in Paramecia
Macronucleus
Micronucleus
MEIOSIS
D. Phylum Sporozoa- sporozoans-no
locomotion- parasites (worms, fish, birds,
humans)-spores-complex life cycle; more than
one host; infects liver and RBC’s- genus
Plasmodium-causes malaria-female Anopholes
Mosquito tranfers sporozoites from salivary glands
mosquito
Mosquito bites human
Liver
Can be transmitted to another mosquito;
Cycle begins again
RBC’s burst open causing chills, fever
Red blood cells
RBC’s infected with merozoites
II. Plant-like Protists- that are unicellular
Importance: produce over 50% of the O2 in
atmosphere by photosynthesis; basis of most
aquatic food chains (phytoplankton); harmful =
algal blooms
A. Euglenophyta-plant & animal-like (auto- or heterotrophic); eye
spot; move towards light; no cell walls (special cell membranepellicle); two flagella; chloroplasts; asexual rep-binary fission
B. Chrysophyta –yellow-green and golden-brown algae-cell walls
made of pectin and/ or cellulose; store food as oil instead of starch;
sexual/ asexual rep.
C. Bacillariophyta-Diatoms-shells made of silica; sexual/ asexual;
pill-box shape; diatomaceous earth is mined for “grit” in toothpaste
and cleaners
Chrysophyta-golden
brown algae
Euglena
chloroplast
eyespot
flagella
Bacillariophyta-Diatoms
D. Dinoflagellates (Pyrrophyta)- ½ photosynthetic; ½ heterotrophs;
mostly asexual-binary fission; two flagella in grooves; spin; many
bioluminescent; some cause red tides; neurotoxin can build up in
Shellfish causing paralysis, illness or death in humans and fish
Karenia brevis
Aerial Views-Red tide-coast
of Maine
III. Plant-like Protists- that are multicellular-Red, Brown
and Green Algae*
A. Red Algae- Rhodophyta- chlorophyll a; phycobilins
(absorbs blue light; so grow at greater depths than other
algae -down to 260m); most multicellular; marine polar
regions to tropics; may be green, purple, or reddish-black;
provide most of calcium carbonate for coral reefs
B. Brown Algae-Phaeophytachlorophylls a and c; fucoxanthin; most
complex of algae, all multicellular;
mostly marine; cool, shallow coastal
waters from temperate to arctic areas;
largest = giant Kelp, grow to 60m; most
common = rockweed; see adaptations
Blades
Bladder
Stipe
Holdfast
C. Green Algae-Chlorophyta-multicellular/ *colonial or
*unicellular; fresh/ marine; moist land; cellulose cell walls;
chlorophylls a and b; store food as starch; possibly ancestor of
plants; alternation of generations like land plants (haploid
gametophyte and diploid sporophyte structures)
IV. Uses and benefits of Algae
A. Base of aquatic food chains; habitat for aquatic life
B. Foods and Medicines- rich in Vitamin C and iron; ice
cream/ yogurt/ pudding/ syrups-texture, Nori (wrap
sushi), treat stomach ulcers, high blood pressure,
arthritis
C. Industry- additives in plastics, waxes, transistors,
deodorants, paints, lubricants,agar (science)
V. Funguslike Protists
A. Cellular Slime Molds
1.retain individual cell membranes throughout life cycle
2. Spend most of life as freeliving amoebas, then when
food is scarce, aggregate
together in a colony forming
fruiting bodies that release
spores that form ameobas
again.
B. Acellular Slime Molds
1. Begin life cycle as amoebas, then aggregate, cells
FUSE and LOSE individual cell membranes; act
as a single, multinucleated organism called a
plasmodium growing several meters in diameter.
2. Sporangia form from
plasmodium producing
haploid spores by meiosis;
spores scatter producing
amoebas (or flagellated
cells); two cells fuse to form
diploid zygotes repeating
the cycle.
C. Water Molds
1. Grow hyphae (filaments) like fungi, but unlike fungi,
and have centrioles, cell walls made of cellulose
instead of chitin; produce motile spores instead of
nonmotile spores
2. Ex: white fuzzy growth on dead fish
D. Ecology of Fungal Protists
1. Decomposers- recyclers of organic material
2. Land dwelling water molds cause numerous plant
diseases ex: grapes, tomatoes
3. Potato Blight (P. infestans)- caused one of the largest
mass immigrations in US History- Great Potato Famine1845-1851- over 1 million Irish people died of starvation;
over 1 million immigrated to the US and other countries
4. Pioneer Species- Lichens- Algae (protist and fungi)-mutualsism
Effects of late
blight lesion on
potato crop
20-1
A protist is any organism that
is not a plant, an animal, a
fungus, or a prokaryote.
A. True
B. False
20-1
– Funguslike protists are
A. autotrophic.
B. photosynthetic.
C. decomposers or parasites.
D. chemosynthetic.
20-1
– Animal-like protists are
A. autotrophs.
B. heterotrophs.
C. decomposers.
D. producers.
20-1
– Biologists have difficulties
classifying protists because
A. their DNA cannot be examined.
B. evidence suggests that they
evolved from so many different
groups.
C. structural similarities used for
classification are difficult to
detect.
D. their ancestors may have evolved
through symbiosis.
20-1
–
An organism is classified as a
protist if it
A. resembles any other member of the
Eukarya domain.
B. shares DNA sequences that are
found only in other protists.
C. has a cell wall made of cellulose.
D. does not belong in any other
kingdom of the Eukarya.
20–2
Structures found in sarcodines
that are used for feeding and
movement are known as
A. pseudopods.
B. flagella.
C. cilia.
D. food vacuoles.
20–2
The structure found in most
ciliates that contains a “reserve
copy” of all the cell's genes is the
A. macronucleus.
B. micronucleus.
C. trichocysts.
D. contractile vacuole.
20–2
One way to classify the various
groups of animal-like protists is by
A. the presence of a nuclear
membrane.
B. the presence of mitochondria.
C. their means of movement.
D. the number of contractile
vacuoles.
20–2
Malaria is caused by the sporozoan
A. Plasmodium.
B. Anopheles.
C. Amoeba.
D. Paramecium.
20–2
Which human disease is caused
by the protist Trypanosoma?
A. measles
B. African sleeping sickness
C. malaria
D. diarrhea
20-3
The function of accessory pigments in
various groups of algae is to
A. absorb red and violet light.
B. carry out photosynthesis in the
absence of chlorophyll.
C. increase the range of wavelengths
used for photosynthesis.
D. carry out photosynthesis when
sunlight is not available.
20-3
Which of the following describes
structures found in
euglenophytes?
A. chloroplasts but no cell walls
B. chloroplasts and cell walls
C. cell walls but no chloroplasts
D. no cell walls or chloroplasts
20-3
Plantlike protists with goldcolored chloroplasts are the
A. euglenophytes.
B. diatoms.
C. chrysophytes.
D. dinoflagellates.
20-3
The base of most marine food
chains is made up of
A. zooplankton.
B. euglenophytes.
C. phytoplankton.
D. chrysophytes.
20-3
The effect of algal “blooms” in the
form of red tides, result in
A. poisoning consumers that eat
filter-feeders such as clams.
B. serving as an important food
source for fish and crustaceans.
C. decomposing other dead and
decaying organisms.
D. converting inorganic molecules
into energy-rich food molecules.
20-4
Reddish accessory pigments found
in red algae are known as
A. chlorophyll a.
B. phycobilins.
C. fucoxanthins.
D. chlorophyll c.
20-4
The giant kelp belongs to the
group known as
A. green algae.
B. brown algae.
C. red algae.
D. golden algae.
20-4
The life cycles of many algae
include
A. haploid generations only.
B. diploid generations only.
C. both haploid and diploid
generations.
D. only asexual reproduction.
20-4
The green alga Chlamydomonas
reproduces asexually by
producing
A. zygotes.
B. gametes.
C. zoospores.
D. holdfasts.
20-4
Cells that can grow into new
organisms without fusing with
another cell are called
A. gametes.
B. spores.
C. gametophytes.
D. sporophytes.
20–5
Unlike the true fungi, funguslike
protists
A. do not have centrioles or cell
walls made of chitin.
B. do not have centrioles but have
cell walls made of chitin.
C. have centrioles but lack cell walls
made of chitin.
D. have both centrioles and cell
walls made of chitin.
20–5
The spore cases formed by water
molds are called
A. zoosporangia.
B. plasmodia.
C. antheridia.
D. sporophytes.
20–5
The acellular slime molds got
their name because
A. they are the only organisms
that do not have cells.
B. they do not have true nuclei.
C. they have multinucleate
hyphae.
D. their cells sometimes fuse to
form structures with many
nuclei.
20–5
Organisms that spend part of their
life cycle as independent,
unicellular amoeba-like forms
and then join together as a visible,
sluglike colony are
A. cellular slime molds.
B. water molds.
C. acellular slime molds.
D. plasmodia.
20–5
The Great Potato Famine was
caused by a(an)
A. cellular slime mold.
B. acellular slime mold.
C. water mold.
D. plasmodia.
20-1
A protist is any organism that
is not a plant, an animal, a
fungus, or a prokaryote.
A. True
B. False
20-1
– Funguslike protists are
A. autotrophic.
B. photosynthetic.
C. decomposers or parasites.
D. chemosynthetic.
20-1
– Animal-like protists are
A. autotrophs.
B. heterotrophs.
C. decomposers.
D. producers.
20-1
– Biologists have difficulties
classifying protists because
A. their DNA cannot be examined.
B. evidence suggests that they
evolved from so many different
groups.
C. structural similarities used for
classification are difficult to
detect.
D. their ancestors may have evolved
through symbiosis.
20-1
–
An organism is classified as a
protist if it
A. resembles any other member of the
Eukarya domain.
B. shares DNA sequences that are
found only in other protists.
C. has a cell wall made of cellulose.
D. does not belong in any other
kingdom of the Eukarya.
20–2
Structures found in sarcodines
that are used for feeding and
movement are known as
A. pseudopods.
B. flagella.
C. cilia.
D. food vacuoles.
20–2
The structure found in most
ciliates that contains a “reserve
copy” of all the cell's genes is the
A. macronucleus.
B. micronucleus.
C. trichocysts.
D. contractile vacuole.
20–2
One way to classify the various
groups of animal-like protists is by
A. the presence of a nuclear
membrane.
B. the presence of mitochondria.
C. their means of movement.
D. the number of contractile
vacuoles.
20–2
Malaria is caused by the sporozoan
A. Plasmodium.
B. Anopheles.
C. Amoeba.
D. Paramecium.
20–2
Which human disease is caused
by the protist Trypanosoma?
A. measles
B. African sleeping sickness
C. malaria
D. diarrhea
20-3
The function of accessory pigments in
various groups of algae is to
A. absorb red and violet light.
B. carry out photosynthesis in the
absence of chlorophyll.
C. increase the range of wavelengths
used for photosynthesis.
D. carry out photosynthesis when
sunlight is not available.
20-3
Which of the following describes
structures found in
euglenophytes?
A. chloroplasts but no cell walls
B. chloroplasts and cell walls
C. cell walls but no chloroplasts
D. no cell walls or chloroplasts
20-3
Plantlike protists with goldcolored chloroplasts are the
A. euglenophytes.
B. diatoms.
C. chrysophytes.
D. dinoflagellates.
20-3
The base of most marine food
chains is made up of
A. zooplankton.
B. euglenophytes.
C. phytoplankton.
D. chrysophytes.
20-3
The effect of algal “blooms” in the
form of red tides, result in
A. poisoning consumers that eat
filter-feeders such as clams.
B. serving as an important food
source for fish and crustaceans.
C. decomposing other dead and
decaying organisms.
D. converting inorganic molecules
into energy-rich food molecules.
20-4
Reddish accessory pigments found
in red algae are known as
A. chlorophyll a.
B. phycobilins.
C. fucoxanthins.
D. chlorophyll c.
20-4
The giant kelp belongs to the
group known as
A. green algae.
B. brown algae.
C. red algae.
D. golden algae.
20-4
The life cycles of many algae
include
A. haploid generations only.
B. diploid generations only.
C. both haploid and diploid
generations.
D. only asexual reproduction.
20-4
The green alga Chlamydomonas
reproduces asexually by
producing
A. zygotes.
B. gametes.
C. zoospores.
D. holdfasts.
20-4
Cells that can grow into new
organisms without fusing with
another cell are called
A. gametes.
B. spores.
C. gametophytes.
D. sporophytes.
20–5
Unlike the true fungi, funguslike
protists
A. do not have centrioles or cell
walls made of chitin.
B. do not have centrioles but have
cell walls made of chitin.
C. have centrioles but lack cell walls
made of chitin.
D. have both centrioles and cell
walls made of chitin.
20–5
The spore cases formed by water
molds are called
A. zoosporangia.
B. plasmodia.
C. antheridia.
D. sporophytes.
20–5
The acellular slime molds got
their name because
A. they are the only organisms
that do not have cells.
B. they do not have true nuclei.
C. they have multinucleate
hyphae.
D. their cells sometimes fuse to
form structures with many
nuclei.
20–5
Organisms that spend part of their
life cycle as independent,
unicellular amoeba-like forms
and then join together as a visible,
sluglike colony are
A. cellular slime molds.
B. water molds.
C. acellular slime molds.
D. plasmodia.
20–5
The Great Potato Famine was
caused by a(an)
A. cellular slime mold.
B. acellular slime mold.
C. water mold.
D. plasmodia.