Chapter 28 Protists
Why have protists been "mixed in" with plants, animals, and fungi under the hypothesis that groups eukaryotes into five supergroups?
Many protists are more closely related to plants, animals, or fungi than they are to each other.
What is a major eukaryotic innovation?
Meiosis
What are oomycetes?
Motile zoospores with two unequal flagella
What is a ulva?
Multicelluar chlorophyte that has identical gametophyte and sporophyte generation and consists of flattened sheets two cells thick.
How do diplomonads move?
Multiple Flagella
All protists are
eukaryotic.
T/F: Some dinoflagellates are luminescent.
True, some are
T/F: Protists are not plant, animal, or fungi.
True, they are their own
What is a raphe?
Two long grooves lined within vibrating fibrils
How many people died from the Irish potato famine and what year did it occur?
1845-1847 which had 400,000 people die
What percentage of the world's photosynthesis is carried out by protists?
30%
31) Which term best describes the symbiotic relationship of well-fed P. bursaria to their zoochlorellae? A) mutualistic B) parasitic C) predatory D) pathogenic
A
39) Refer to the study by Poulsen et al. and the figure above. Cultures of a species of diatom were treated with BDM, a reversible inhibitor of myosin function. Which of the following predictions is consistent with the hypothesis that an actin-myosin interaction is necessary for motility? A) BDM will significantly decrease motility of the cells in culture. B) BDM will not significantly alter motility of the cells in culture. C) BDM will significantly increase motility of the cells in culture.
A
Paulinella chromatophora is one of the few cercozoans that is autotrophic, carrying out aerobic photosynthesis with its two elongated "chromatophores." The chromatophores are contained within vesicles of the host cell, and each is derived from a cyanobacterium, though not the same type of cyanobacterium that gave rise to the chloroplasts of algae and plants. 40) P. chromatophora secretes around itself a test, or case, of plates made of silica. Which of the following is another rhizarian that would be in competition with P. chromatophora for the silica needed to make these plates, assuming limited quantities of silica in the environment? A) radiolarians B) foraminiferans C) dinoflagellates D) diatoms
A
Similar to most amoebozoans, the forams and the radiolarians also have pseudopods, as do the white blood cells of animals. If one were to erect a taxon that included all organisms that have cells with pseudpods, what would be true of such a taxon? A) It would be polyphyletic. B) It would be paraphyletic. C) It would be monophyletic. D) It would include all eukaryotes.
A
The best evidence for not classifying the slime molds as fungi comes from slime moldsʹ A) DNA sequences. B) nutritional modes. C) choice of habitats. D) physical appearance. E) reproductive methods.
A
What do ciliates contain and what does it do? (Besides 2 nuclei)
A pellicle which is a tough, flexible outer covering
What are apical complexes?
A unique arrangement of organelles at one end of the cell.
How were the Charales and Coleochaetales clades thought to be closely related to land plants?
Both form green mats around edges of freshwater ponds and marshes.
What do rhodophyta contain within themselves?
Accessory photosynthetic pigments which are often red
How did mitochondria specifically evolved from endosymbiosis?
Aerobic bacteria engulfed by larger bacteria.
What are cilia?
Aid in locomotion of protists but are shorter and more numerous than flagella.
Who use pseudopodia as a means for locomotion?
Amoeba
Where do dinoflagellates live in?
Aquatic environments
How do protists typically reproduce?
Asexually
15) When a mosquito infected with Plasmodium first bites a human, the Plasmodium _____. A) gametes fuse, forming an oocyst B) cells infect the human liver cells C) cells cause lysing of the human red blood cells D) oocyst undergoes meiosis
B
20) Which of the following is characteristic of ciliates? A) They use pseudopods as feeding structures. B) They are often multinucleate. C) They can exchange genetic material with other ciliates by the process of mitosis. D) Most live as solitary autotrophs in fresh water
B
21) Diatoms are mostly asexual members of the phytoplankton. Diatoms lack any organelles that might have the 9 + 2 pattern. They obtain their nutrition from functional chloroplasts, and each diatom is encased within two porous, glasslike valves. Which question would be most important for one interested in the day-to-day survival of individual diatoms? A) How do diatoms get transported from one location on the water's surface layers to another location on the surface? B) How do diatoms with their glasslike valves keep from sinking into poorly lit waters? C) How do diatoms with their glasslike valves avoid being shattered by the action of waves? D) How do diatom sperm cells locate diatom egg cells?
B
24) A snail-like, coiled, porous test (shell) of calcium carbonate is characteristic of _____. A) diatoms B) foraminiferans C) ciliates D) water molds
B
33) A P. bursaria cell that has lost its zoochlorellae is said to be aposymbiotic . It might be able to replenish its contingent of zoochlorellae by ingesting them without subsequently digesting them. Which of the following situations would be most favorable to the reestablishment of resident zoochlorellae, assuming compatible Chlorella are present in P. bursaria' s habitat? A) abundant light, no bacterial prey B) abundant light, abundant bacterial prey C) no light, no bacterial prey D) no light, abundant bacterial prey
B
34) A P. bursaria cell that has lost its zoochlorellae is aposymbiotic . If aposymbiotic cells have population growth rates the same as those of healthy, zoochlorella-containing P. bursaria in well- lit environments with plenty of prey items, then such an observation would be consistent with which type of relationship? A) parasitic B) commensalistic C) toxic D) mutualistic
B
4) All protists are _____. A) unicellular B) eukaryotic C) symbionts D) mixotrophic
B
43) The genome of modern chloroplasts is roughly 50% the size of the genome of the cyanobacterium from which it is thought to have been derived. In comparison, the genome of P. chromatophora 's chromatophore is only slightly reduced relative to the size of the genome of the cyanobacterium from which it is thought to have been derived. What is a valid hypothesis that can be drawn from this comparison? A) Lytic phage infections have targeted the chloroplast genome more often than the P. chromatophora genome. B) P. chromatophora 's chromatophore is the result of an evolutionarily recent endosymbiosis. C) The genome of the chloroplast ancestor contained many more introns that could be lost without harm, compared to the chromatophore's genome. D) The genome of the cyanobacteria was smaller than the genome of P. chromatophora
B
50) Previously understood similarities that seemed to connect slime molds and fungi are now considered to be _____. A) homologies B) examples of convergent evolution C) variations of common ancestral traits D) adaptations for much different functions
B
52) Super cells characteristic of plasmodial slime molds result when which one of the following common cellular processes does not occur? A) mitosis B) cytokinesis C) aerobic metabolism D) endocytosis
B
56) Living diatoms contain brownish plastids. If global warming causes blooms of diatoms in the surface waters of Earth's oceans, how might this be harmful to the animals that build coral reefs? A) The coral animals, which capture planktonic organisms, may be outcompeted by the diatoms. B) The coral animals' endosymbiotic dinoflagellates may get "shaded out" by the diatoms. C) The coral animals may die from overeating the plentiful diatoms with their cases of silica. D) The diatoms' photosynthetic output may over-oxygenate the water
B
7) The closest living relative of P. chromatophora is the heterotroph P. ovalis. P. ovalis uses threadlike pseudopods to capture its prey, which it digests internally. Which of the following, if observed, would be the best reason for relabeling P. chromatophora as a mixotroph instead of an autotroph? A) a pigmented central vacuole, surrounded by a tonoplast B) a vacuole with food inside C) a secretory vesicle D) a contractile vacuole
B
8) Which process could have allowed the nucleomorphs of chlorarachniophytes to be reduced, without the net loss of any genetic information? A) conjugation B) horizontal gene transfer C) phagocytosis D) meiosis
B
A snail-like, coiled, porous test (shell) of calcium carbonate is characteristic of which group? A) diatoms B) foraminiferans C) radiolarians D) gymnamoebas E) ciliates
B
According to the endosymbiotic theory of the origin of eukaryotic cells, how did mitochondria originate? A) from infoldings of the plasma membrane, coupled with mutations of genes for proteins in energy-transfer reactions B) from engulfed, originally free-living prokaryotes C) by secondary endosymbiosis D) from the nuclear envelope folding outward and forming mitochondrial membranes E) when a protoeukaryote engaged in a symbiotic relationship with a protobiont
B
Biologists suspect that endosymbiosis gave rise to mitochondria before plastids partly because A) the products of photosynthesis could not be metabolized without mitochondrial enzymes. B) all eukaryotes have mitochondria (or their remnants), whereas many eukaryotes do not have plastids. C) mitochondrial DNA is less similar to prokaryotic DNA than is plastid DNA. D) without mitochondrial CO2 production, photosynthesis could not occur. E) mitochondrial proteins are synthesized on cytosolic ribosomes, whereas plastids utilize their own ribosomes.
B
Green algae often differ from land plants in that some green algae A) are heterotrophs. B) are unicellular. C) have plastids. D) have alternation of generations. E) have cell walls containing cellulose.
B
Protists are alike in that all are: A) unicellular. B) eukaryotic. C) symbionts. D) monophyletic. E) autotrophic.
B
The strongest evidence for the endosymbiotic origin of eukaryotic organelles is the similarity between extant prokaryotes and which of the following? A) nuclei and chloroplasts B) mitochondria and chloroplasts C) cilia and mitochondria D) mitochondria and nuclei E) mitochondria and cilia
B
Which of the following statements concerning protists is false? A) All protists are eukaryotic organisms; many are unicellular or colonial. B) The primary organism that transmits malaria to humans by its bite is the tsetse fly. C) All apicomplexans are parasitic. D) Cellular slime molds have an amoeboid stage that may be followed by a stage during which spores are produced. E) Euglenozoans that are mixotrophic contain chloroplasts.
B
Which of these statements is false and therefore does not support the hypothesis that certain eukaryotic organelles originated as bacterial endosymbionts? Such organelles A) are roughly the same size as bacteria. B) can be cultured on agar, because they make all their own proteins. C) contain circular DNA molecules. D) have ribosomes that are similar to those of bacteria. E) have internal membranes that contain proteins homologous to those of bacterial plasma membranes.
B
Which of these taxa contains species that produce potent toxins that can cause extensive fish kills, contaminate shellfish, and poison humans? A) red algae B) dinoflagellates C) diplomonads D) euglenids E) golden algae
B
How can protists reproduce?
Both asexually and sexually
What do plasmodial slime molds ingest?
Bacteria and other organic materia
What does euglenozoa have the ability to do and why?
Bodies morph when swimming due to lack of cell wall
19) You are given an unknown organism to identify. It is unicellular and heterotrophic. It is motile, using many short extensions of the cytoplasm, each featuring the 9 + 2 filament pattern. It has well-developed organelles and two nuclei, one large and one small. This organism is most likely to be a _____. A) foraminiferan B) radiolarian C) ciliate D) kinetoplastid
C
22) A large seaweed that floats freely on the surface of deep bodies of water would be expected to lack which of the following? A) thalli B) bladders C) holdfasts D) gel-forming polysaccharides
C
26) A gelatinous seaweed that grows in shallow, cold water and undergoes heteromorphic alternation of generations is most probably what type of alga? A) red B) green C) brown D) yellow
C
29) Water's density and, consequently, its buoyancy decrease at warmer temperatures. Based on this consideration and using data from the table above, at which time of year should one expect diatoms to be storing excess calories mostly as oil? A) mid-winter B) early spring C) late summer D) late fall
C
3) A particular species of protist has obtained a chloroplast via secondary endosymbiosis. You know this because the chloroplasts _____. A) have nuclear and cyanobacterial genes B) are exceptionally small C) have three or four membranes D) have only a single pigmen
C
32) The motility that permits P. bursaria to move toward a light source is provided by _____. A) pseudopods B) a single flagellum featuring the 9 + 2 pattern C) many cilia D) contractile vacuoles
C
A gelatinous seaweed that grows in shallow, cold water and undergoes heteromorphic alternation of generations is most probably what type of alga? A) red B) green C) brown D) yellow
C
An individual mixotroph loses its plastids, yet continues to survive. Which of the following most likely accounts for its continued survival? A) It relies on photosystems that float freely in its cytosol. B) It must have gained extra mitochondria when it lost its plastids. C) It engulfs organic material by phagocytosis or by absorption. D) It has an endospore. E) It is protected by a siliceous case.
C
Diatoms are mostly asexual members of the phytoplankton. Diatoms lack any organelles that might have the 9+2 pattern. They obtain their nutrition from functional chloroplasts, and each diatom is encased within two porous, glasslike valves. Which question would be most important for one interested in the day-to-day survival of individual diatoms? A) How does carbon dioxide get into these protists with their glasslike valves? B) How do diatoms get transported from one location on the waterʹs surface layers to another location on the surface? C) How do diatoms with their glasslike valves keep from sinking into poorly lit waters? D) How do diatoms with their glasslike valves avoid being shattered by the action of waves? E) How do diatom sperm cells locate diatom egg cells?
C
Giardia intestinalis is an intestinal parasite of humans and other mammals that causes intestinal ailments in most people who ingest the cysts. Upon ingestion, each cyst releases two motile cells, called trophozoites. These attach to the small intestine's lining via a ventral adhesive disk. The trophozoites anaerobically metabolize glucose from the host's intestinal contents to produce ATP. Reproduction is completely asexual, occurring by longitudinal binary fission of trophozoites, with each daughter cell receiving two haploid nuclei (n = 5). A trophozoite will often encyst as it passes into the large intestine by secreting around itself a case that is resistant to cold, heat, and dehydration. Infection usually occurs by drinking untreated water that contains cysts. 9) The cysts of Giardia function most like the _____. A) mitochondria of ancestral diplomonads B) nuclei of archaeans C) endospores of bacteria D) capsids of viruses
C
If the Archaeplastidae are eventually designated a kingdom, and if the land plants are excluded from this kingdom, then what will be true of this new kingdom? A) It will be monophyletic. B) It will more accurately depict evolutionary relationships than does the current taxonomy. C) It will be paraphyletic. D) It will be a true clade. E) It will be polyphyletic.
C
Which of the following is not characteristic of ciliates? A) They use cilia as locomotory structures or as feeding structures. B) They are relatively complex cells. C) They can exchange genetic material with other ciliates by the process of mitosis. D) Most live as solitary cells in fresh water. E) They have two or more nuclei.
C
Which pair of alternatives is highlighted by the life cycle of the cellular slime molds, such as Dictyostelium? A) prokaryotic or eukaryotic B) plant or animal C) unicellular or multicellular D) diploid or haploid E) autotroph or heterotroph
C
Why is the filamentous morphology of the water molds considered a case of convergent evolution with the hyphae (threads) of fungi? A) Fungi are closely related to the water molds. B) Body shape reflects ancestor-descendant relationships among organisms. C) In both cases, filamentous shape is an adaptation for the absorptive nutritional mode of a decomposer. D) Filamentous body shape is evolutionarily ancestral for all eukaryotes. E) Both A and B are correct.
C
12) The mitosome of Giardia has no DNA within it. If it did contain DNA, then what predictions should we be able to make about its DNA? 1. It is linear. 2. It is circular. 3. It has many introns. 4. It has few introns. 5. It is not associated with histone proteins. 6. It is complexed with histone proteins. A) 1, 3, and 5 B) 1, 4, and 5 C) 2, 3, and 6 D) 2, 4, and 5
D
42) If true, which of the following would be most important in determining whether P. chromatophora 's chromatophore is still an endosymbiont, or is an organelle, as the term chromatophore implies? A) if P. chromatophora is less fit without its chromatophore than with it B) if the chromatophore is less fit without the host cercozoan than with it C) if there is ongoing metabolic cooperation between the chromatophore and the host cercozoan D) if there has been movement of genes from the chromatophore genome to the nuclear genome, such that these genes are no longer present in the chromatophore genome
D
48) Which of the following groups is matched with a correct anatomical feature? A) foraminifera→silicon-rich tests B) dinoflagellata→holdfast C) diatoms→tests made of cellulose D) phaeophyta (brown algae)→ blade
D
49) Unikonta is a supergroup that includes all of the following except _____. A) fungi B) protists C) animals D) plants
D
51) Branching points at the root of the eukaryotic phylogenetic tree A) reveal that unikonts are derived from the SAR clade B) suggest that Archaeplastids were the first eukaryotes C) strongly suggest that fungi are more closely related to plants than animals D) are presently unclear
D
58) If we were to apply the most recent technique used to fight potato late blight to the fight against the malarial infection of humans, then we would _____. A) increase the dosage of the least-expensive antimalarial drug administered to humans B) introduce a predator of the malarial parasite into infected humans C) use a "cocktail" of at least three different pesticides against Anopheles mosquitoes D) insert genes from a Plasmodium -resistant strain of mosquito into Anopheles mosquitoes
D
6) Which of the following have chloroplasts (or structures since evolved from chloroplasts) thought to be derived from ancestral green algae? A) stramenopiles B) apicomplexans C) dinoflagellates D) chlorarachniophytes
D
A large seaweed that floats freely on the surface of deep bodies of water would be expected to lack which of the following? A) thalli B) bladders C) blades D) holdfasts E) gel-forming polysaccharides
D
In life cycles with an alternation of generations, multicellular haploid forms alternate with A) unicellular haploid forms. B) unicellular diploid forms. C) multicellular haploid forms. D) multicellular diploid forms. E) multicellular polyploid forms.
D
Plastids that are surrounded by more than two membranes are evidence of A) evolution from mitochondria. B) fusion of plastids. C) origin of the plastids from archaea. D) secondary endosymbiosis. E) budding of the plastids from the nuclear envelope.
D
When light, especially red and blue light, is shone on the tubes, oxygen bubbles accumulate on the inside of test tubes 1 and 2. Chemical analysis of test tube 1 indicates the presence of a chemical that is toxic to fish and humans. Chemical analysis of test tube 2 indicates the presence of substantial amounts of silica. Microscopic analysis of organisms in test tubes 1, 3, and 4 reveals the presence of permanent, membrane-bounded sacs just under the plasma membrane. Microscopic analysis of organisms in test tube 3 reveals the presence of an apicoplast in each. Microscopic analysis of the contents in test tube 4 reveals the presence of one large nucleus and one small nucleus in each organism. 27) Test tube 3 contains _____. A) Paramecium B) Pfiesteria (dinoflagellate) C) Entamoeba D) Plasmodium
D
Which of the following is correctly described as a primary producer? A) oomycete B) kinetoplastid C) apicomplexan D) diatom E) radiolarian
D
Which statement regarding resistance is false? A) Many of the oomycetes that cause potato late blight have become resistant to pesticides. B) Many of the mosquitoes that transmit malaria to humans have become resistant to pesticides. C) Many of the malarial parasites have become resistant to antimalarial drugs. D) Many humans have become resistant to antimalarial drugs. E) Trichomonas vaginalis is resistant to the normal acidity of the human vagina.
D
You are given the task of designing an aerobic, mixotrophic protist that can perform photosynthesis in fairly deep water (e.g., 250 m deep), and can also crawl about and engulf small particles. With which two of these structures would you provide your protist? 1. hydrogenosome 2. apicoplast 3. pseudopods 4. chloroplast from red alga 5. chloroplast from green alga A) 1 and 2 B) 2 and 3 C) 2and4 D) 3 and 4 E) 4 and 5
D
What evidence is endosymbiosis supported by?
DNA in mitochondria and chloroplast similar to bacteria DNA in size. Ribosomes in mitochondria are similar to bacterial ribosomes. Chloroplasts and mitochondria replicate through binary fission.
What is an example of a protist with an extracellular matric?
Diatoms which have silica shells
What are cysts?
Dormant cells with resistant outer covering used for disease transmission.
What role do diatoms play in the global carbon balance affecting global warming?
During a bloom, diatom populations may increase rapidly. If many diatoms die and sink to the bottom without being eaten, they effectively pump carbon dioxide out of the atmosphere.
Which of these statements about dinoflagellates is false? A) They possess two flagella. B) Some cause red tides. C) Their walls are composed of cellulose plates. D) Many types contain chlorophyll. E) Their dead cells accumulate on the seafloor, and are mined to serve as a filtering material.
E
Which organisms represent the common ancestor of all photosynthetic plastids found in eukaryotes? A) autotrophic euglenids B) diatoms C) dinoflagellates D) red algae E) cyanobacteria
E
Which protists are in the same eukaryotic ʺsupergroupʺ as land plants? A) green algae B) dinoflagellates C) red algae D) brown algae E) A and C are both correct
E
Which taxon of eukaryotic organisms is thought to be directly ancestral to the plant kingdom? A) golden algae B) radiolarians C) foraminiferans D) apicomplexans E) green algae
E
Which of the following statements supports the hypothesis of an endosymbiotic origin of mitochondria?
Each mitochondrion has its own DNA molecule.
How did mitochondria and chloroplasts arise?
Endosymbiosis between an ancestral eukaryote and bacterial cell.
How can some amoeba be parasitic?
Enter the body through a wound and crosses the blood-brain barrier into the brain causing inflammation and death.
What are the sizes of the daughter cells in mitosis?
Equal sizes to one another
What organisms are members of the euglenozoa group?
Euglenids and parasitic kinetoplastids
What is the earliest eukaryote to possess mitochondria?
Euglenozoa
What are the supergroups of protists?
Excavata, amoebozoa, chromalveolata, rhizaria, ophistokonta, archaeplastida
Who can die from the toxins of dinoflagellates?
Fish, birds, and marine mammals
What organism is a member of the diplomonads ?
Giardia
How did the nucleus and endoplasmic reticulum arise?
Infoldings of prokaryotic cell membrane
What does the apical complex allow apicomplexans to do?
Invade its hosts
What are brown algae NOT?
NOT plants
What is an example of a ciliate?
Paramecium
What do phototrophs ingest?
Particulate food matter
What is a type of heterotroph?
Phagotroph
What type of autotroph are dinoflagellates and are they uni or multi cellular?
Photosynthetic and are unicellular
_____ are eukaryotic autotrophs that float near the surface of water and are the basis of the food chain.
Phytoplankton
How do trypanosomes withstand the attack of a host's immune system?
The molecular composition of their surface changes continually.
What do the Choanoflagellida multicellular colonial forms resemble?
Their close animal relatives the common ancestor of sponges
Which of the following is characteristic of ciliates?
They are often multinucleate.
What do chlorophyta have that is unusual?
Unusual diversity and lines of specialization
Many types of foraminiferans form a symbiotic relationship with _____.
algae
Biologists think that endosymbiosis gave rise to mitochondria before plastids partly because
all eukaryotes have mitochondria (or their remnants), whereas many eukaryotes do not have plastids.
Which of the following are actual mutualistic partnerships that involve a protist and a host organism?
all except that involving humans
Stemonitis is a slime mold. Which of the following is it most closely related to?
an amoeba
You are designing an artificial drug-delivery "cell" that can penetrate animal cells. Which of these protist structures should provide the most likely avenue for research along these lines?
apical complex
Which protists are in the same eukaryotic supergroup as land plants?
both red algae and green algae
Stramenopiles include all of the following groups EXCEPT ______. water molds diatoms golden algae brown algae cellular slime molds
cellular slime molds
You discover a new species of slime mold that has a spore and stalk consisting of many cells. Which group does it belong with?
cellular slime molds
Which algal group has chloroplasts much like those of green plants in structure and pigment makeup?
chlorophytes
A paramecium is a(n) _____.
ciliate
All of the organisms classified as _____ move and feed using cilia.
ciliates
Which of these groups is characterized by cells that have more than one nucleus?
ciliates
How do ciliates generate genetic variation?
conjugation
Which process results in genetic recombination, but is separate from the process by which the population size of Paramecium increases?
conjugation
Biologists have long been aware that the defunct kingdom Protista is paraphyletic. Which of these statements is both true and consistent with this conclusion? A) Many species within this kingdom were once classified as monerans. B) Animals, plants, and fungi arose from different protist ancestors. C) The eukaryotic condition has evolved only once among the protists, and all eukaryotes are descendants of that first eukaryotic cell. D) Chloroplasts among various protists are similar to those found in prokaryotes. E) Some protists, all animals, and all fungi share a protist common ancestor, but these protists, animals, and fungi are currently assigned to three different kingdoms.
e
Which of these groups consist of parasitic flagellated cells, such as Trypanosoma, the organism that causes sleeping sickness?
kinetoplastids
Organisms are classified as Excavata based on
morphological studies of the cytoskeleton
In life cycles with an alternation of generations, multicellular haploid forms alternate with
multicellular diploid forms.
Which of these algal groups possess a photosynthetic pigment that allows them to live in deep water?
red algae
Hypermastigotes are important endosymbionts that live in the guts of __________.
termites
How many nuclei do diplomonads have?
2
How many types of vacuoles to ciliates have?
2
18) Dinoflagellates _____. A) possess two flagella B) are all autotrophic C) lack mitochondria D) include species that cause malaria
A
What are the groups within stramenopiles of the supergroup chromalveolate?
Brown algae Diatoms Oomycetes
47) Similar to most amoebozoans, the forams and the radiolarians also have pseudopods, as do some of the white blood cells of animals (monocytes). If one were to erect a taxon that included all organisms that have cells with pseudopods, the taxon would _____. A) be polyphyletic B) be paraphyletic C) be monophyletic D) include all eukaryotes
A
How many lineages do green algae have?
2
How many nuclei do celiates have?
2
45) Green algae differ from land plants in that many green algae _____. A) are unicellular B) have plastids C) have alternation of generations D) have cell walls containing cellulose
A
53) Which of the following is responsible for nearly 100,000 human deaths worldwide every year? A) Entamoeba histolytica B) Amoeba proteus C) plasmodial slime molds D) Dictyostelium discoideum
A
The chloroplasts of land plants are thought to have been derived according to which evolutionary sequence? A) cyanobacteria green algae land plants B) cyanobacteria green algae fungi land plants C) red algae brown algae green algae land plants D) red algae cyanobacteria land plants E) cyanobacteria red algae green algae land plants
A
Thread-like pseudopods that can perform phagocytosis are generally characteristic of which group? A) radiolarians and forams B) gymnamoebas C) entamoebas D) amoeboid stage of cellular slime molds E) oomycetes
A
The largest seaweeds belong to which group? A) red algae B) green algae C) brown algae D) golden algae
C
Which group includes members that are important primary producers in ocean food webs, causes red tides that kill many fish, and may even be carnivorous? A) ciliates B) apicomplexans C) dinoflagellates D) brown algae E) golden algae
C
What are the 2 lineages of green algae?
Chlorophyta and charophytes
What locomotion aids opisthokonts?
Singular posterior flagellum
Which term describes the fusion of two gametes to form a diploid zygote?
Syngamy
What do stramenopiles have on their flagella?
Very fine hairs on their flagella
Plasmodium, the parasitic organism that causes malaria, is a _____.
apicomplexan
Which of these groups includes parasitic unicellular organisms with a complex of organelles specialized for penetrating host cells and tissues?
apicomplexans Apicomplexans are parasites of animals. The apex of the sporozoite cell contains a complex of organelles specialized for penetrating host cells and tissues, hence the name "Apicomplexa."
A sign on the beach states, "Beach Closed. Red Tide." The organisms interfering with your use of this beach are probably _____.
dinoflagellates
Which of these groups includes species that produce a substance that is toxic to humans
dinoflagellates
Which organisms are capable of producing a "red tide"?
dinoflagellates
The cells of _____ and _____ have modified mitochondria.
diplomonads ...parabasalids
Which of the following are two groups that are adapted to anaerobic conditions and contain modified mitochondria that lack DNA?
diplomonads and parabasalids
What does the supergroup excavata consist of?
diplomonads, parabasalids, and euglenozoans
The red algae are characterized by __________.
diverse life cycles, including alternation of generations Not all their species are red. The color of the organism depends on what water depth it inhabits.
What is the purpose of the "floats" in some brown algae?
facilitating photosynthesis
T/F: All stramenopiles have fine hairs on their flagella.
False, a few species have lost their hairs during evolution
What do plasmodial slime molds form?
Feeding phases
True or false? Organisms that exhibit alternation of generations reproduce sexually in the diploid stage.
False
How is the green algae of charophytes distinguishable from green algae of chlorophytes and what evidence provides that?
Phylogenetic relationship to land plants evidence from rRNA and DNA sequences.
What organism is a member of oomycetes?
Phytophthora infestans
__________ is a protist that causes late blight of potatoes and was responsible for the Irish potato famine of the 19th century.
Phytophthora infestans In recent years, scientists have discovered that the protist is showing resistance to pesticides. Efforts to place genes from wild potato plants that are resistant to infection into domestic potatoes have been successful.
What sort of reproduction do oomycetes go through?
Sexual
Where can amoeba be found?
soil and freshwater
You are researching the reproduction of slime molds. Which of the following do you study?
spores
In many types of protist life cycles, the union of two gametes that results in a diploid zygote is called __________.
syngamy
Apicomplexans are currently assigned to the SAR clade because __________.
the apicoplast, a modified plastid, appears to be of red algal origin
Of the eukaryotic kingdoms who is the most diverse?
Protists
Which of the following is true?
Slime molds colonized land before plants and animals.
What does the DNA of dinoflagellates not have?
Histones
What are the 2 nuclei's of celiates?
Macronucleus and micronucleus
What is the nickname for pseudopodia?
"False feet"
T/F: Protists can only have one flagella for locomotion.
False, there can be more than one.
What do diplomonads lack?
Mitochondria
Do parabasilids have a mitochondria?
Yes, but it is semifunctional
What is the nickname of oomycetes?
"Water molds"
pair with its description
1.) apicomplexans-parasites with intricate life cycles 2.) diatoms-important producers in aquatic communities 3.) diplomonads-protists with modified mitochondria
1) According to the endosymbiotic theory, why was it adaptive for the larger (host) cell to keep the engulfed cell alive, rather than digesting it as food? A) The engulfed cell provided the host cell with adenosine triphosphate (ATP). B) The engulfed cell provided the host cell with carbon dioxide. C) The engulfed cell allowed the host cell to metabolize glucose. D) The host cell was able to survive anaerobic conditions with the engulfed cell alive
A
13) Given its mode of reproduction and internal structures, which of the following should be expected to occur in Giardia at some stage of its life cycle? A) separation (segregation) of daughter chromosomes B) crossing over C) meiosis
A
16) Which two genera have members that can evade the human immune system by frequently changing their surface proteins? 1. Plasmodium 2.Trichomonas 3.Paramecium 4.Trypanosoma 5.Entamoeba A) 1 and 4 B) 2 and 3 C) 2 and 4 D) 4 and 5
A
2) The chloroplasts of land plants are thought to have been derived according to which evolutionary sequence? A) cyanobacteria→green algae→land plants B) cyanobacteria→green algae→fungi→ land plants C) red algae→brown algae→green algae→land plants D) cyanobacteria→red algae→green algae →land plants
A
23) Reinforced, threadlike pseudopods that can perform phagocytosis are generally characteristic of _____. A) forams B) water molds C) dinoflagellates D) oomycetes
A
25) You are given the task of designing an aquatic protist that is a primary producer. It cannot swim on its own, yet must stay in well-lit surface waters. It must be resistant to physical damage from wave action. It should be most similar to a(n) _____. A) diatom B) dinoflagellate C) apicomplexan D) red alga
A
38) Refer to the study by Poulsen et al. and the figure above. The data graphed in the figure could be an artifact if latrunculin A kills this species of diatoms (that is, that may be why the cells are not moving). Which of the following would be the best evidence that latrunculin A is NOT killing the cells? A) When the toxin was washed off the culture, the cells began to move again. B) There were still a small percentage of motile cells in the culture treated with the toxin. C) Most of the cells in the control were moving, indicating that they were alive. D) When the toxin was applied to another species of diatom, 25% of them continued to move
A
41) Including the membrane of the surrounding vesicle, how many phospholipid (NOT lipopolysaccharide) bilayers should be found around each P. chromatophora 's chromatophore, and which one of these bilayers should have photosystems embedded in it? A) two; innermost B) two; outermost C) three; innermost D) three; outermost
A
44) A biologist discovers an alga that is marine, multicellular, and lives at a depth reached only by blue light. This alga is most likely a type of _____. A) red algae B) brown algae C) green algae D) golden algae
A
When light, especially red and blue light, is shone on the tubes, oxygen bubbles accumulate on the inside of test tubes 1 and 2. Chemical analysis of test tube 1 indicates the presence of a chemical that is toxic to fish and humans. Chemical analysis of test tube 2 indicates the presence of substantial amounts of silica. Microscopic analysis of organisms in test tubes 1, 3, and 4 reveals the presence of permanent, membrane-bounded sacs just under the plasma membrane. Microscopic analysis of organisms in test tube 3 reveals the presence of an apicoplast in each. Microscopic analysis of the contents in test tube 4 reveals the presence of one large nucleus and one small nucleus in each organism. 28) Test tube 4 contains _____. A) Paramecium B) Pfiesteria (dinoflagellate) C) Entamoeba D) Plasmodium
A
Which of these was not derived from an ancestral alpha proteobacterium? A) chloroplast B) mitochondrion C) hydrogenosome D) mitosome E) kinetoplast
A
You are given the task of designing an aquatic protist that is a primary producer. It cannot swim on its own, yet must stay in well-lit surface waters. It must be resistant to physical damage from wave action. It should be most similar to a(n) A) diatom. B) dinoflagellate. C) apicomplexan. D) red alga. E) radiolarian.
A
Which characteristic is/are shared by most diatoms, golden algae, and brown algae at least at some stage of their life cycles?
All are stramenopiles. All are autotrophs. They all have flagella with numerous fine, hairlike projections.
What do a carnivorous dinoflagellate, a parasitic apicomplexan, and a ciliate have in common?
All three have sacs known as alveoli just beneath their plasma membranes.
What is the advantage of sexual reproduction of protists?
Allows frequent genetic recombination
The members of _____ are characterized by cells with small membrane-bounded cavities under their cell membranes.
Alveolata
What are the branches of chromalveolata?
Alveolates and stramenopiles
What do alveolates include?
Alveoli which are flattened vessicles
What organism is a member of amoeba?
Amoeba proteus
What is the sub group of amoebazoa?
Amoebazoans
Which of the following is true of secondary endosymbiosis?
An organism containing an endosymbiont is engulfed by another organism and becomes an endosymbiont.
54) Assume that some members of an aquatic species of motile, photosynthetic protists evolve to become parasitic to fish. They gain the ability to live in the fish gut, absorbing nutrients as the fish digests food. Over time, which of the following phenotypic changes would you expect to observe in this population of protists? A) loss of motility B) loss of chloroplasts C) gain of a rigid cell wall D) gain of meiosis
B
What makes certain red algae appear red? A) They live in warm coastal waters. B) They possess pigments that reflect and transmit red light. C) They use red light for photosynthesis. D) They lack chlorophyll. E) They contain the pigment bacteriorhodopsin.
B
Which example below is a characteristic shared by diplomonads and parabasalids?
Both lack plastids.
What are mixotrophs?
Both phototrophic and heterotrophic
What is an example of secondary endosymbiosis?
Brown algae engulf red algae that contain chloroplasts.
10) Consider the following data: (a) Most ancient eukaryotes are unicellular. (b) All eukaryotes alive today have a nucleus and cytoskeleton. (c) Most ancient eukaryotes lack a cell wall. Which of the following conclusions could reasonably follow the data presented? The first eukaryote may have been _____. A) very similar to a plant cell B) anaerobic C) capable of phagocytosis D) photosynthetic
C
11) Giardia's mitosome can be said to be "doubly degenerate," because it is a degenerate type of ________, an organelle that is itself a degenerate form of ________. A) nucleus; archaean B) nucleus; bacterium C) mitochondria; proteobacterium D) mitochondria; spirochete
C
14) If the mitosomes of Giardia contain no DNA, yet are descendants of what were once free- living organisms, then where are we likely to find the genes that encode their structures, and what accounts for their current location there? A) plasmids; conjugation B) plasmids; transformation C) nucleus; horizontal gene transfer D) nucleus; S phase
C
17) Which of the following pairs of protists and their characteristics is mismatched? A) apicomplexans — internal parasites B) euglenozoans — unicellular flagellates C) ciliates — red tide organisms D) entamoebas — ingestive heterotrophs
C
30) Water's density and, consequently, its buoyancy decrease at warmer temperatures. Considering the impact of temperature, and the table above, in which environment should diatoms sinking be slowest? A) cold fresh water B) warm fresh water C) cold seawater D) warm seawater
C
35) Theoretically, P. bursaria can obtain zoochlorella either vertically (via the asexual reproduction of its mother cell) or horizontally (by ingesting free-living Chlorella from its habitat). Consider a P. bursaria cell containing zoochlorellae but whose habitat lacks free-living Chlorella . If this cell subsequently undergoes many generations of asexual reproduction, if all of its daughter cells contain roughly the same number of zoochlorellae as it had originally contained, and if the zoochlorellae are all haploid and identical in appearance, then what is true? The zoochlorellae _____. A) also reproduced asexually, at an increasing rate over time B) also reproduced asexually, at a decreasing rate over time C) also reproduced asexually, at a fairly constant rate over time D) reproduced sexually, undergoing heteromorphic alternation of generations
C
36) Which process in Paramecium results in genetic recombination but no increase in population size? A) budding B) meiotic division C) conjugation D) binary fission
C
37) Refer to the study by Poulsen et al. and the figure above. Latrunculin A is a reversible toxin that disrupts the formation of actin fibers. A culture of a particular species of diatom was treated with this toxin diluted in a buffer, while another culture was treated only with the buffer (no toxin; control). The motility of cells in each culture was assessed by counting the number of cells that were moving during a defined period of time. Which of the following conclusions is reasonable based on the above figure? A) Formation of actin fibers is not necessary for the movement in this species of diatom. B) The buffer alone largely inhibited movement in this species of diatom. C) In this species of diatom, fully formed actin fibers are necessary for movement.
C
46) You are given the task of designing an aerobic, mixotrophic protist that can perform photosynthesis in fairly deep water (for example, 250 meters deep) and can also crawl about and engulf small particles. With which two of the following structures would you provide your protist? 1. hydrogenosome 2. apicoplast 3. pseudopods 4. chloroplast from red alga 5. chloroplast from green alga A) 1 and 2 B) 2 and 3 C) 3 and 4 D) 4 and 5
C
5) An individual mixotroph loses its plastids, yet continues to survive. Which of the following most likely accounts for its continued survival? A) It relies on photosystems that float freely in its cytosol. B) It must have gained extra mitochondria when it lost its plastids. C) It engulfs organic material by phagocytosis or by absorption. D) It has an endospore.
C
57) Which of the following is a producer? A) kinetoplastid B) apicomplexan C) diatom D) ciliates
C
Which structure mediates the attachment of spores to a surface on which to grow?
Holdfast
What is Schizogony?
Cell division preceded by multiple nuclear divisions producing several individuals.
What clades were thought to be related to land plants?
Charales and coleochaetales
What gave rise to land plants?
Charophytes
What are the types of autotrophs?
Chemoautotrophic and photosynthetic
What is the subgroup of opisthokonta?
Choanoflagellida
Where did chloroplasts come from?
Cyanobacteria
Healthy individuals of Paramecium bursaria contain photosynthetic algal endosymbionts of the genus Chlorella . When within their hosts, the algae are referred to as zoochlorellae. In aquaria with light coming from only one side, P. bursaria gather at the well-lit side, whereas other species of Paramecium gather at the opposite side. The zoochlorellae provide their hosts with glucose and oxygen, and P. bursaria provides its zoochlorellae with protection and motility. P. bursaria can lose its zoochlorellae in two ways: (1) if kept in darkness, the algae will die; and (2) if prey items (mostly bacteria) are absent from its habitat, P. bursaria will digest its zoochlorellae. 55) Which term most accurately describes the nutritional mode of healthy P. bursaria ? A) photoautotroph B) photoheterotroph C) chemoautotroph D) mixotroph
D
What are some ways we have tried to eradicate plasmodium?
Mosquito vector Drug development Vaccines
What subgroups do alveolates include?
Dinoflagellates Apicomplexans Ciliates
Coral bleaching, which causes high coral mortality, has been occurring widely in coral reefs. Coral bleaching actually refers to the death of symbiotic dinoflagellates living within the corals. Why does coral bleaching cause the corals to die?
Dinoflagellates provide nutrients from the products of photosynthesis to the corals in exchange for a safe place to live.
What do rhodophyta lack?
Flagella and centrioles
What do parabasilids use for locomotion?
Flagella and undulating membrane
What are the sources of locomotion for protists?
Flagella, cilia, and pseudopodia
What are the types of vacuoles of ciliates?
Food vacuoles- digestion of food Contractile vacuoles- regulation of water balance
What do plasmodial slime molds do when food or moisture is scarce?
Form spores in sporangia
How do chemoautotrophics obtain energy?
From oxidation of inorganic compounds
How do photosynthetic autotrophs obtain energy?
From the sun
What were oomycetes once considered to be?
Fungi
Which term describes the multicellular haploid form of a protist that shows alternation of generations?
Gametophyte
How does the haploid form of Ulva "switch" to its diploid form?
Gametophytes produce cells that undergo mitosis to produce gametes that fuse to form a zygote.
What are radiolarians composed of?
Glassy exoskeletons made of silica
What type of life cycle do brown algae have and what do they involve?
Haplodiplontic life cycle involving alteration of generations
Which of the following statements about Ulva's haploid stage is true?
Haploid cells are produced by meiosis of diploid cells.
What is the composition of Choanoflagellida?
Have single emergent flagellum surrounded by a funnel-shaped, contractile collar
What is the anatomy of euglena?
Have two anterior, unequal flagella, contractile vacuoles that collect excess water, stigma to move towards light, and numerous small chloroplasts
How do we describe the mitosis of asexually reproducing protists?
Have unusual mitosis
What are foraminifera?
Heterotrophic marine protists
Why is the filamentous morphology of the water molds considered a case of convergent evolution with fungi?
In both cases, filamentous shape is an adaptation for the absorptive nutritional mode of a decomposer.
Where can haplodiplontic life cycles be found?
In some chlorophytes and the streptophytes
Where do parabasilids live and what type of relationship do they have?
In termite guts and have a symbiotic relationship with cellulose-degrading bacteria
where can oomycetes be found?
In water or land
An individual mixotroph loses its plastids, yet continues to survive. Which of the following most likely accounts for its continued survival?
It engulfs organic material by phagocytosis or by absorption.
Which of the following is one of the main weaknesses of the proposed classification scheme in which all eukaryotes are divided into four supergroups?
It shows all four supergroups diverging simultaneously from a common ancestor.
If the Archaeplastidae are eventually designated a kingdom, and if land plants are excluded from this kingdom, then what will be true of this new kingdom?
It will be paraphyletic.
Similar to most amoebozoans, the forams and the radiolarians also have pseudopods, as do some of the white blood cells of animals (monocytes). If one were to erect a taxon that included all organisms that have cells with pseudopods, what would be true of such a taxon?
It would be polyphyletic.
What are ciliates?
Large numbers of cilia arranged in longitudinal rows or spirals around a cell that beat in a coordinated fashion
How did chloroplasts specifically evolve from endosymbiosis?
Larger bacteria engulfed photosynthetic bacteria.
What besides pseudopods aids amoeba in movements?
Microfilaments of actin and myosin
What are protists not?
Monophyletic
What form of locomotion do radiolarians use?
Needle-like pseudopods
What are the sizes of the daughter cells in budding?
One daughter cell is smaller than the other
How may have chromalveolates supergroups have risen?
One or more secondary endosymbiotic events.
What type of autotroph are diatoms and are they uni or multi cellular?
Photosynthetic autotroph that are unicellular
What are limestones rich in and where can they be found?
Rich in foraminifera and found in white cliffs of dover.
What organism is a member of apicomplexans have and what do they cause?
Plasmodium which causes malaria
What does foraminifera use for feeding?
Podia
What is the "Red Tide"?
Population explosions of dinoflagellates
What are tests and where are they found?
Pore which are studded shells found in foraminifera
How do amoeba move?
Pseudopods
What helps amoeba engulf food particles?
Pseudopods
What are the subgroups of rhizaria?
Radiolaria Foraminifera Cercozoa
How do diatoms move?
Raphes
What are rhodophyta?
Red algae that range from microscopic to being very large.
What are the subgroups within archaeplastida?
Rhodophyta Chlorophyta Land plants
Why has the kingdom Protista been abandoned?
Some protists are more closely related to plants, animals, or fungi than they are to other protists. Some protists are as small as prokaryotes.
Which of the following is true?
Some species of slime molds form colonies.
What are apicomplexans?
Spore-forming animal parasites
Which group is characterized by cells with fine hairlike projections on their flagella?
Stramenopila
What are plasmodial slime molds?
Stream along as plasmodium which are nonwalled, multinucleate mass of cytoplasm.
Where do podia emerge from?
Tests
What did phytophthora infestans cause?
The Irish potato famine of 1845-1847 which had 400,000 people die
Based on the phylogenetic tree in Figure 28.2, which of the following statements is correct?
The most basal (first to diverge) eukaryotic supergroup cannot be determined.
Based on the phylogenetic tree in Figure 28.3 in your textbook, which of the following statements is correct?
The most basal (first to diverge) eukaryotic supergroup cannot be determined.
What are the varied arrays of cell surfaces within protists?
The plasma membrane and the extracellular matrix in some.
In lab class, a plasmodial slime mold is used as a demonstration organism. One of the students does not understand why this organism is not considered multicellular. How would you explain it to her?
The plasmodium is undivided by membranes and contains many diploid nuclei; therefore, it is not technically multicellular.
What do brown algae make up?
The seaweeds of northern regions
What advantage do organisms that reproduce sexually have over organisms that reproduce asexually?
Their offspring may be more adaptable to changes in the environment.
How do protists vary from other eukaryotes?
They can be uni or multi celllular and colonial. Most are microscopic, but some large All symmetries Use all types of nutrition
How do amoeba move through pseudopods?
They extend and pull amoeba forward.
What is the life cycle of plasmodium?
They go from being sexual to asexual and go in different hosts.
What are heterotrophs?
They obtain their energy from organic compounds made by other organisms.
Which of the following statements about dinoflagellates is true?
They possess two flagella.
How did one species move to land successfully from the Charales and Coleochaetales clades?
Through adaptations to drying.
What organism is a member of parabasilids?
Trichomonas vaginalis (an STD)
Are choanoflagellida uni or multicellular?
Unicellular
Are diplomonads multicellular or unicellular?
Unicellular
What is produced by meiosis?
Union of haploid gametes
What are diatoms composed of?
Unique double shells made of silica
Healthy individuals of Paramecium bursaria contain photosynthetic algal endosymbionts of the genus Chlorella. When within their hosts, the algae are referred to as zoochlorellae. In aquaria with light coming from only one side, P. bursaria gathers at the well-lit side, whereas other species of Paramecium gather at the opposite side. The zoochlorellae provide their hosts with glucose and oxygen, and P. bursaria provides its zoochlorellae with protection and motility. P. bursaria can lose its zoochlorellae in two ways: (1) if kept in darkness, the algae will die; and (2) if prey items (mostly bacteria) are absent from its habitat, P. bursaria will digest its zoochlorellae. A P. bursaria cell that has lost its zoochlorellae is said to be aposymbiotic. It might be able to replenish its contingent of zoochlorellae by ingesting them without subsequently digesting them. Which of the following situations would be most favorable to the reestablishment of resident zoochlorellae, assuming compatible Chlorella are present in P. bursaria's habitat?
abundant light, abundant bacterial prey
A gelatinous seaweed that grows in shallow, cold water and undergoes heteromorphic alternation of generations is most probably what type of alga?
brown
The largest seaweeds are _____.
brown algae
Which of the following organisms is commercially harvested to extract algin from their cell walls?
brown algae
Which three groups contain large algae known as seaweeds?
brown algae, red algae, and green algae
Healthy individuals of Paramecium bursaria contain photosynthetic algal endosymbionts of the genus Chlorella. When within their hosts, the algae are referred to as zoochlorellae. In aquaria with light coming from only one side, P. bursaria gathers at the well-lit side, whereas other species of Paramecium gather at the opposite side. The zoochlorellae provide their hosts with glucose and oxygen, and P. bursaria provides its zoochlorellae with protection and motility. P. bursaria can lose its zoochlorellae in two ways: (1) if kept in darkness, the algae will die; and (2) if prey items (mostly bacteria) are absent from its habitat, P. bursaria will digest its zoochlorellae. A P. bursaria cell that has lost its zoochlorellae is aposymbiotic. If aposymbiotic cells have population growth rates the same as those of healthy, zoochlorella-containing P. bursaria in well-lit environments with plenty of prey items, then such an observation would be consistent with which type of relationship?
commensalistic
The chloroplasts of land plants are thought to have been derived according to which evolutionary sequence?
cyanobacteria → green algae → land plants
Archaeplastids, which include red and green algae and land plants, are thought to have descended from a heterotrophic protist that engulfed a(n) _____.
cyanobacterium
You are given the task of designing an aquatic protist that is a primary producer. It cannot swim on its own, yet must stay in well-lit surface waters. It must be resistant to physical damage from wave action. It should be most similar to a(n)
diatom
Which of these groups includes unicellular organisms that, due to the structure of their cell walls, can withstand pressures equal to the pressure under each leg of a table supporting an elephant?
diatoms
Which of these groups is characterized by glasslike walls containing silica?
diatoms
Which of these groups includes photosynthetic unicellular organisms with flagella and contractile vacuoles?
euglenids
Paulinella chromatophora is one of the few cercozoans that is autotrophic, carrying out aerobic photosynthesis with its two elongated "cyanelles." The cyanelles are contained within vesicles of the host cell, and each is derived from a cyanobacterium, though not the same type of cyanobacterium that gave rise to the chloroplasts of algae and plants. The closest living relative of P. chromatophora is the heterotroph, P. ovalis. What type of evidence permits biologists to make this claim about relatedness?
genetic
Which of the following groups of algae is/are most closely related to land plants?
green algae
Healthy individuals of Paramecium bursaria contain photosynthetic algal endosymbionts of the genus Chlorella. When within their hosts, the algae are referred to as zoochlorellae. In aquaria with light coming from only one side, P. bursaria gathers at the well-lit side, whereas other species of Paramecium gather at the opposite side. The zoochlorellae provide their hosts with glucose and oxygen, and P. bursaria provides its zoochlorellae with protection and motility. P. bursaria can lose its zoochlorellae in two ways: (1) if kept in darkness, the algae will die; and (2) if prey items (mostly bacteria) are absent from its habitat, P. bursaria will digest its zoochlorellae. The motility that permits P. bursaria to move toward a light source is provided by
many cilia.
Giardia intestinalis is an intestinal parasite of humans and other mammals that causes intestinal ailments in most people who ingest the cysts. Upon ingestion, each cyst releases two motile cells, called trophozoites. These attach to the small intestine's lining via a ventral adhesive disk. The trophozoites anaerobically metabolize glucose from the host's intestinal contents to produce ATP. Reproduction is completely asexual, occurring by longitudinal binary fission of trophozoites, with each daughter cell receiving two, haploid nuclei (n = 5). A trophozoite will often encyst as it passes into the large intestine by secreting around itself a case that is resistant to cold, heat, and dehydration. Infection usually occurs by drinking untreated water that contains cysts. Giardia's mitosome can be said to be "doubly degenerate," because it is a degenerate form of ________, an organelle that is itself a degenerate form of ________.
mitochondrion; proteobacterium
Healthy individuals of Paramecium bursaria contain photosynthetic algal endosymbionts of the genus Chlorella. When within their hosts, the algae are referred to as zoochlorellae. In aquaria with light coming from only one side, P. bursaria gathers at the well-lit side, whereas other species of Paramecium gather at the opposite side. The zoochlorellae provide their hosts with glucose and oxygen, and P. bursaria provides its zoochlorellae with protection and motility. P. bursaria can lose its zoochlorellae in two ways: (1) if kept in darkness, the algae will die; and (2) if prey items (mostly bacteria) are absent from its habitat, P. bursaria will digest its zoochlorellae. Which term most accurately describes the nutritional mode of healthy P. bursaria?
mixotroph
in life cycles with an alternation of generations, multicellular haploid forms alternate with
multicellular diploid forms.
Healthy individuals of Paramecium bursaria contain photosynthetic algal endosymbionts of the genus Chlorella. When within their hosts, the algae are referred to as zoochlorellae. In aquaria with light coming from only one side, P. bursaria gathers at the well-lit side, whereas other species of Paramecium gather at the opposite side. The zoochlorellae provide their hosts with glucose and oxygen, and P. bursaria provides its zoochlorellae with protection and motility. P. bursaria can lose its zoochlorellae in two ways: (1) if kept in darkness, the algae will die; and (2) if prey items (mostly bacteria) are absent from its habitat, P. bursaria will digest its zoochlorellae. Which term best describes the symbiotic relationship of well-fed P. bursaria to their zoochlorellae?
mutualistic
Which of these groups includes both aquatic decomposers and the parasites responsible for late potato blight?
oomycetes
Golden algae, brown algae, red algae, chlorophytes, and charophyceans are some examples of protists that are _____.
photosynthetic
Plastids that are surrounded by more than two membranes are evidence of
secondary endosymbiosis.
Conjugation in ciliates is _____, resulting in the production of two genetically novel individuals combining the genes of two parents. It is not reproduction, because no additional individuals are produced, although it is followed by reproduction.
sexual
Which of the following is a characteristic of the water molds (oomycetes)?
the presence of filamentous feeding structures
On some areas of the seafloor, one could observe an "ooze" that is hundreds of meters thick. What creates this ooze?
the tests of dead radiolarians
Many species of red algae are adapted to deeper water due to the fact that __________.
their photosynthetic pigments efficiently absorb blue and green light
The placement of all protists in one kingdom caused dissatisfaction among taxonomists mainly because __________.
various pieces of evidence indicate that the kingdom Protista cannot be monophyletic