Transcript Document
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 Zoomastigina harmful or helpful; sleeping sickness; termite guts to digest wood; mostly asexual (mitosis/cytokinesis); some sexual rep. where (gametes fuse)
Trypanosoma brucei Giardia gambiense-
African
Trichonympha –
campers/ sleeping sickness termite gut hikers
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 Mosquito tranfers sporozoites from salivary glands 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 O 2 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 membrane pellicle); 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
Euglena chloroplast
Chrysophyta-golden brown algae Bacillariophyta-
Diatoms eyespot flagella
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-Phaeophyta chlorophylls
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 free living 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 Famine 1845-1851- 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 gold colored 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 gold colored 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.