Bio test 1

Which of the following taxonomic categories contains all the others listed here?
a) order
b) species
c) class
d) family
e) genus

The best classification system is that which most closely…
a) conforms to traditional, Linnaean taxonomic practices.
b) reflects evolutionary history.
c) reflects the basic separation of prokaryotes from eukaryotes.
d) unites organisms that possess similar morphologies.

Some molecular data place the giant panda in the bear family (Ursidae) but place the lesser panda in the raccoon family (Procyonidae). Consequently, the morphological similarities of these two species are probably due to…
a) possession of shared primitive characters.
b) inheritance of acquired characteristics.
c) sexual selection.
d) possession of analogous structures.
e) inheritance of shared derived characters

Which process occurred frequently in the early history of the three domains on Earth, and makes determining phylogenetic relationships of that time difficult?
a) horizontal gene transfer
b) binary fission
c) alternative RNA splicing
d) meiosis
e) mitosis

Prokaryotic cells are found in the domain(s)…
a) Bacteria and Archaea
b) Bacteria and Eukarya
c) Bacteria and Protista
d) Bacteria
e) Protista and Archaea

In the five-kingdom system, prokaryotes are placed in the kingdom
a) Protista
b) Animalia
c) Fungi
d) Plantae
e) Monera

In the five-kingdom system, which kingdom consists primarily of unicellular eukaryotes?
a) Fungi
b) Protista
c) Plantae
d) Animalia
e) Monera

In the two-kingdom system, why were fungi classified in the kingdom Plantae?
a) They are sedentary.
b) They are heterotrophs.
c) They lack cell walls.
d) They are unicellular.
e) They are autotrophs

There is(are) _____ eukaryotic domain(s).
a) 1
b) 2
c) 3
d) 4
e) 5

For a proponent of PhyloCode classification, what is true of the reptile clade if birds are not included in it?
a) It becomes a superclass, whereas the birds remain a class.
b) It becomes a subclass, instead of a class.
c) PhyloCode does not concern itself with what is, or is not, a clade.
d) It becomes paraphyletic and, thus, an invalid reflection of evolutionary history

Traditionally, zoologists have placed birds in their own class, Aves. More recently, molecular evidence has shown that birds are more closely related to reptiles than their anatomy reveals. Genetically, birds are more closely related to crocodiles than crocodiles are to turtles. Thus, bird anatomy has become highly modified as they have adapted to flight, without their genes having undergone nearly as much change.
Taxonomically, what should be done with the birds?
a) The rest of the reptiles should be reclassified as a subclass within the class Aves.
b) The birds should be reclassified, and their new taxon should be the subclass Aves. Genetic similarity trumps morphological dissimilarity in cases where morphological traits are uninformative.
c) The classification scheme should remain the same because of historical precedence.
d) The traditional stance is correct. Such dramatic morphological change as undergone by birds merits that the birds be placed in their own order, separate from the reptiles.

The importance of computers and of computer software to modern cladistics is most closely linked to advances in
a) Linnaean classification.
b) radiometric dating.
c) molecular genetics.
d) light microscopy.
e) fossil discovery techniques

The common ancestors of birds and mammals were very early (stem) reptiles, which almost certainly possessed three-chambered hearts (two atria, one ventricle). Birds and mammals, however, are alike in having four-chambered hearts (two atria, two ventricles). The four-chambered hearts of birds and mammals are best described as
a) vestiges.
b) homoplasies.
c) structural homologies.
d) the result of shared ancestry.
e) molecular homologies

Which observation supports the position of eukaryotes at the convergence of the “ring of life”?
a) Only eukaryotes perform mitosis.
b) Introns are rare in both bacteria and archaeans.
c) Eukaryotes and archaeans both lack peptidoglycan in their cell walls.
d) The nuclear genome of eukaryotes contains genes from archaeans and from bacteria.
e) Circular chromosomes are present in both bacteria and archaeans

What kind of evidence has recently made it necessary to assign the prokaryotes to either of two different domains, rather than assigning all prokaryotes to the same kingdom?
a) ecological
b) behavioral
c) molecular
d) nutritional
e) anatomica

Which eukaryotic kingdom is polyphyletic, and therefore unacceptable, based on cladistics?
a) Protista
b) Plantae
c) Animalia
d) Fungi
e) Monera

Though plants, fungi, and prokaryotes all have cell walls, we place them in different taxa. Which of these observations comes closest to explaining the basis for placing these organisms in different taxa, well before relevant data from molecular systematics became available?
a) Some have cell walls only for support.
b) Some have cell walls only to control osmotic balance.
c) Their cell walls are composed of very different biochemicals.
d) Some closely resemble animals, which lack cell walls.
e) Some have cell walls only for protection from herbivores

Which statement about bacterial cell walls is false?
a) Bacterial cell walls are similar in function to the cell walls of many protists, fungi, and plants.
b) Cell walls provide the cell with a degree of physical protection from the environment.
c) Bacterial cell walls differ in molecular composition from plant cell walls.
d) Cell walls prevent cells from bursting in hypotonic environments.
e) Cell walls prevent cells from dying in hypertonic conditions.

Jams, jellies, preserves, honey, and other foodstuffs with high sugar content hardly ever become contaminated by bacteria, even when the food containers are left open at room temperature. This is because bacteria that encounter such an environment
a) experience lysis.
b) are obligate anaerobes.
c) are unable to swim through these thick and viscous materials.
d) are unable to metabolize the glucose or fructose, and thus starve to death.
e) undergo death as a result of water loss from the cell

In a bacterium that possesses antibiotic resistance and the potential to persist through very adverse conditions, such as freezing, drying, or high temperatures, DNA should be located within, or be part of, which structures?
1. nucleoid region
2. endospore
3. fimbriae
4. plasmids

a) 2 and 4 only
b) 1 and 4 only
c) 1, 2, and 4
d) 1 and 2 only
e) 1 only

The typical prokaryotic flagellum features
a) a complex “motor” embedded in the cell wall and plasma membrane.
b) an external covering provided by the plasma membrane.
c) a basal body that is similar in structure to the cell’s centrioles.
d) an internal 9 + 2 pattern of microtubules.
e) a membrane-enclosed organelle with motor proteins

Prokaryotic ribosomes differ from those present in eukaryotic cytosol. Because of this, which of the following is correct?
a) Prokaryotes are unable to use a greater variety of molecules as food sources than can eukaryotes.
b) Eukaryotes did not evolve from prokaryotes.
c) Some antibiotics can block the synthesis of peptidoglycan in the walls of bacteria.
d) Some antibiotics can block protein synthesis in bacteria without effects in the eukaryotic host.
e) Translation can occur at the same time as transcription in eukaryotes but not in prokaryotes.

Which statement about the genomes of prokaryotes is correct?
a) Prokaryotic genomes are diploid throughout most of the cell cycle.
b) Prokaryotic chromosomes are sometimes called plasmids.
c) Prokaryotic genomes are composed of circular DNA.
d) Prokaryotic cells have multiple chromosomes, “packed” with a relatively large amount of protein.
e) The prokaryotic chromosome is not contained within a nucleus but, rather, is found at the nucleolus

If a bacterium regenerates from an endospore that did not possess any of the plasmids that were contained in its original parent cell, the regenerated bacterium will probably also
a) lack antibiotic-resistant genes.
b) be unable to survive in its normal environment.
c) lack water in its cytoplasm.
d) lack a chromosome.
e) lack a cell wall

Prokaryotes’ essential genetic information is located in the
a) exospore.
b) nucleoid.
c) nucleosome.
d) nucleolus.
e) plasmids

Hershey and Chase performed an elegant experiment that convinced most biologists that DNA, rather than protein, was the genetic material. This experiment subjected bacteria to the same gene transfer mechanism as occurs in
a) transformation.
b) conjugation.
c) endosymbiosis.
d) binary fission.
e) transduction

How does the large amount of genetic variation observed in prokaryotes arise?
a) The mutation rate in prokaryotes is much higher than in eukaryotes.
b) They have extremely short generation times and large populations.
c) They can exchange DNA with many types of prokaryotes by way of horizontal gene transfer.
d) They have a relatively small genome.
e) The second and third answers are correct

Genes for the resistance of antibiotics are usually located
a) on the main chromosome
b) in mitochondria
c) in eukaryotic cells
d) on the outside of the cell wall
e) on plasmids

Which of these statements about prokaryotes is correct?
a) Bacterial cells conjugate to mutually exchange genetic material.
b) The persistence of bacteria throughout evolutionary time is due to their genetic homogeneity (in other words, sameness).
c) Genetic variation in bacteria is not known to occur, because of their asexual mode of reproduction.
d) They divide by binary fission, without mitosis or meiosis.
e) Their genetic material is confined within vesicles known as plasmids

Bacteria that live around deep-sea, hot-water vents obtain energy by oxidizing inorganic hydrogen sulfide belched out by the vents. They use this energy to build organic molecules from carbon obtained from the carbon dioxide in seawater. These bacteria are
a) chemoheterotrophs
b) chemoautotrophs
c) photoautotrophs
d) photoheterotrophs

Which statement is true about obligate anaerobes?
a) They are poisoned by O2.
b) They use O2 for cellular respiration and cannot grow without it.
c) They live exclusively by cellular respiration or by anaerobic respiration.
d) They will use O2 if it is present, but can obtain energy by fermentation if needed.
e) They obtain energy by oxidizing ferrous ions

Chloramphenicol is an antibiotic that targets prokaryotic (70S) ribosomes, but not eukaryotic (80S) ribosomes. Which of these questions stems from this observation, plus an understanding of eukaryotic origins?
a) How is translation affected in ribosomes that are targeted by chloramphenicol?
b) Can chloramphenicol also be used to control human diseases that are caused by archaeans?
c) If chloramphenicol inhibits prokaryotic ribosomes, should it not also inhibit mitochondrial ribosomes?
d) Why aren’t prokaryotic ribosomes identical to eukaryotic ribosomes?
e) Can chloramphenicol pass through the capsules possessed by many cyanobacteria?

Which of the following obtain energy by oxidizing inorganic substances to obtain energy that is used, in part, to fix CO2?
a) photoheterotrophs
b) chemoheterotrophs that perform decomposition
c) parasitic chemoheterotrophs
d) chemoautotrophs
e) photoautotrophs

Given that the enzymes that catalyze nitrogen fixation are inhibited by oxygen, what are two “strategies” that nitrogen-fixing prokaryotes might use to protect these enzymes from oxygen?
1. couple them with photosystem II (the photosystem that splits water molecules)
2. package them in membranes that are impermeable to all gases
3. be obligate anaerobes
4. be strict aerobes
5. package these enzymes in specialized cells or compartments that inhibit oxygen entry

a) 2 and 5
b) 3 and 5
c) 3 and 4
d) 2 and 4
e) 1 and 4

Bacteria that live around deep-sea, hot-water vents obtain energy by oxidizing inorganic hydrogen sulfide belched out by the vents. They use this energy to build organic molecules from carbon obtained from the carbon dioxide in seawater. These bacteria are
a) photoautotrophs
b) photoheterotrophs
c) chemoheterotrophs
d) chemoautotrophs

Match the numbered terms to the description that follows. Choose all appropriate terms.
1. autotroph
2. heterotroph
3. phototroph
4. chemotroph
a prokaryote that obtains both energy and carbon as it decomposes dead organisms
a) 4 only
b) 2 and 4
c) 1 and 3
d) 1 only
e) 1, 3, and 4

Match the numbered terms to the description that follows. Choose all appropriate terms.
1. autotroph
2. heterotroph
3. phototroph
4. chemotroph
an organism that obtains both carbon and energy by ingesting prey

a) 2 and 4
b) 1 and 3
c) 4 only
d) 1 only
e) 1, 3, and 4

Match the numbered terms to the description that follows. Choose all appropriate terms.
1. autotroph
2. heterotroph
3. phototroph
4. chemotroph
an organism that obtains energy from light

a) 1, 3, and 4
b) 1 and 3
c) 3 only
d) 2 and 4
e) 1 only

Which of the following obtain energy by oxidizing inorganic substances to obtain energy that is used, in part, to fix CO2?
a) photoautotrophs
b) parasitic chemoheterotrophs
c) chemoautotrophs
d) photoheterotrophs
e) chemoheterotrophs that perform decomposition

Which group was not described in Woese’s tree of life analysis?
a) Bacteria
b) Prokarya
c) Archaea
d) Eukarya

What characteristics were used to classify organisms before Woese’s tree of life analysis?
a) Differences in ribosomal RNA sequences
b) Number of cells in the organism
c) Presence of a membrane-bound nucleus
d) Composition of the cell wall

True or false? Data showing that the Bacteria were the first lineage to diverge from the common ancestor of all living organisms suggest that the Archaea and Eukarya are more closely related to each other than they are to the Bacteria

Which of the following statements about phylogenetic trees is true?
a) A paraphyletic group consists of a common ancestor and some of its descendants.
b) A paraphyletic group consists of an ancestral population and all of its descendants.
c) A paraphyletic group has not experienced lateral gene transfer.
d) A monophyletic group consists of a common ancestor and some of its descendants

Which molecule did Carl Woese study to produce his tree of life?
a) Ribosome
b) Ribosomal RNA
c) DNA
d) Messenger RNA

What is lateral gene transfer?
a) Physical transfer of a gene from a species in one lineage to a species in another lineage.
b) Inheritance of a gene from a parent
c) Inheritance of a gene through meiosis
d) Inheritance of a gene through mitosis

The prokaryotic organisms most likely to be found living in salt ponds are the
a) thermophiles
b) methanogens
c) Korarchaeota
d) extremophiles
e) halophiles

How are archaeans most similar to bacteria?
a) the occurrence of introns in their chromosomes
b) nucleotide sequence of small subunit ribosomal RNA
c) the shape of their chromosomes and plasmids
d) methanogenesis
e) the structure of their cell walls

Mitochondria are thought to be the descendants of certain alpha proteobacteria. They are, however, no longer able to lead independent lives because most genes originally present on their chromosome have moved to the nuclear genome. Which phenomenon accounts for the movement of these genes?
a) horizontal gene transfer
b) translation
c) plasmolysis
d) conjugation
e) endocytosis

The thermoacidophile, Sulfolobus acidocaldarius, lacks peptidoglycan, but still possesses a cell wall. What is likely to be true of this species?
1. It is a bacterium.
2. It is an archaean.
3. The optimal pH of its enzymes will lie above pH 7.
4. The optimal pH of its enzymes will lie below pH 7.
5. It could inhabit certain hydrothermal springs.
6. It could inhabit alkaline hot springs

a) 1, 4, and 5
b) 2, 4, and 6
c) 2, 4, and 5
d) 1, 3, and 6
e) 1, 3, and 5

A fish that has been salt-cured subsequently develops a reddish color. You suspect that the fish has been contaminated by the extreme halophile, Halobacterium. Which of these features of cells removed from the surface of the fish, if confirmed, would support your suspicion?
1. the presence of the same photosynthetic pigments found in cyanobacteria
2. cell walls that lack peptidoglycan
3. cells that are isotonic to conditions on the surface of the fish
4. cells unable to survive salt concentrations lower than 9%
5. the presence of very large numbers of ion pumps in its plasma membrane

a) 3, 4, and 5
b) 1, 4, and 5
c) 2 and 5
d) 2, 3, 4, and 5
e) 3 and 4

An ecological relationship between organisms of different species that are in direct contact can best be described as
a) taxis
b) parasitic
c) commensal
d) symbiotic
e) mutualistic

The termite gut protist, Mixotricha paradoxa, has at least two kinds of bacteria attached to its outer surface. One kind is a spirochete that propels its host through the termite gut. A second type of bacteria synthesizes ATP, some of which is used by the spirochetes. The locomotion provided by the spirochetes introduces the ATP-producing bacteria to new food sources. Which term(s) is (are) applicable to the relationship between the two kinds of bacteria?
1. mutualism
2. parasitism
3. symbiosis
4. metabolic cooperation
a) 2, 3, and 4
b) 1, 3, and 4
c) 1 only
d) 1 and 2
e) 2 and 3

In general, what is the primary ecological role of prokaryotes?
a) serving as primary producers in terrestrial environments
b) breaking down organic matter
c) adding methane to the atmosphere
d) metabolizing materials in extreme environments
e) parasitizing eukaryotes, thus causing diseases

If all prokaryotes on Earth suddenly vanished, which of the following would be the most likely and most direct result?
a) The recycling of nutrients would be greatly reduced, at least initially.
b) There would be no more pathogens on Earth.
c) Bacteriophage numbers would dramatically increase.
d) Human populations would thrive in the absence of disease.
e) The number of organisms on Earth would decrease by 10-20%

In a hypothetical situation, a bacterium lives on the surface of a leaf, where it obtains nutrition from the leaf’s nonliving, waxy covering while inhibiting the growth of other microbes that are plant pathogens. If this bacterium gains access to the inside of a leaf, however, it causes a fatal disease in the plant. Once the plant dies, the bacterium and its offspring decompose the plant. What is the correct sequence of ecological roles played by the bacterium in the situation described here? Use only those that apply.
1. nutrient recycler
2. mutualist
3. commensal
4. pathogen
5. primary producer
a) 2, 3, 4
b) 1, 2, 5
c) 2, 4, 1
d) 1, 2, 3
e) 1, 3, 4

Bioremediation is
a) the use of prokaryotes in producing pharmaceutical products
b) the modification of prokaryotes for industrial purposes
c) the use of organisms to remove pollutants from the environment
d) the use of prokaryotes in producing transgenic organisms
e) the use of biological processes to remedy diseases

Foods can be preserved in many ways by slowing or preventing bacterial growth. Which of these methods should be least effective at inhibiting bacterial growth?
a) Irradiation: kills bacteria by mutating their DNA to such an extent that their DNA-repair enzymes are overwhelmed.
b) Canning in heavy sugar syrup: creates osmotic conditions that remove water from most bacterial cells.
c) Refrigeration: slows bacterial metabolism and growth.
d) Closing previously opened containers: prevents more bacteria from entering, and excludes O2.
e) Pickling: creates a pH at which most bacterial enzymes cannot function

Broad-spectrum antibiotics inhibit the growth of most intestinal bacteria. Consequently, assuming that nothing is done to counter the reduction of intestinal bacteria, a hospital patient who is receiving broad-spectrum antibiotics is most likely to become
a) unable to synthesize peptidoglycan.
b) deficient in certain vitamins and nutrients.
c) antibiotic resistant.
d) unable to fix carbon dioxide.
e) unable to fix nitrogen

Genetic variation in bacterial populations cannot result from
a) transduction.
b) transformation.
c) meiosis.
d) mutation.
e) conjugation

Which of the following statements is not true?
a) Only bacteria have histones associated with DNA.
b) Both archaea and bacteria generally lack membrane-enclosed organelles.
c) Only some archaea use CO2 to oxidize H2, releasing methane.
d) The cell walls of archaea lack peptidoglycan.
e) Archaea and bacteria have different membrane lipids

Bacteria perform the following ecological roles. Which role typically does not involve symbiosis?
a) gut mutualist
b) aggregate with methane-consuming archaea
c) decomposer
d) pathogen
e) skin commensalist

Select the correct statement about bacteria
a) Certain bacteria live within rocks kilometers below the Earth’s surface.
b) All organisms with cells containing a membrane-enclosed nucleus and organelles are eukaryotes, whereas all organisms with cells lacking a membrane-enclosed nucleus and organelles are bacteria.
c) The majority of bacteria cause human disease

Which of the following is true of secondary endosymbiosis?
a) It is indicated by the presence of a double membrane surrounding the endymbiont.
b) An organism containing one endosymbiont engulfs another organism, and that organism becomes an endosymbiont.
c) It is indicated by the presence of a nucleomorph.
d) An organism containing an endosymbiont is engulfed by another organism and becomes an endosymbiont.
e) It is indicated by the presence of a mixotroph

All protists are
a) unicellular.
b) monophyletic.
c) mixotrophic.
d) eukaryotic.
e) symbionts

According to the endosymbiotic theory of the origin of eukaryotic cells, how did mitochondria originate?
a) by secondary endosymbiosis
b) when a protoeukaryote engaged in a symbiotic relationship with a protocell
c) from engulfed, originally free-living proteobacteria
d) from the nuclear envelope folding outward and forming mitochondrial membranes
e) from infoldings of the plasma membrane, coupled with mutations of genes for proteins in energy-transfer reactions

An individual mixotroph loses its plastids, yet continues to survive. Which of the following most likely accounts for its continued survival?
a) It has an endospore.
b) It is protected by a case made of silica.
c) It must have gained extra mitochondria when it lost its plastids.
d) It relies on photosystems that float freely in its cytosol.
e) It engulfs organic material by phagocytosis or by absorption

Which of the following was derived from an ancestral cyanobacterium?
a) hydrogenosome
b) mitosome
c) mitochondrion
d) chloroplast
e) Two of the responses above are correct

The chloroplasts of land plants are thought to have been derived according to which evolutionary sequence?
a) red algae → brown algae → green algae → land plants
b) cyanobacteria → green algae → land plants
c) cyanobacteria → red algae → green algae → land plants
d) cyanobacteria → green algae → fungi → land plants

Which of the following are two groups that are adapted to anaerobic conditions and contain modified mitochondria that lack DNA?
a) dinoflagellates and diatoms
b) chlorophytes and radiolarians
c) apicomplexans and forams
d) gymnamoebas and slime molds
e) diplomonads and parabasalids

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) 2 and 4
b) 1 and 4
c) 2 and 3
d) 1 and 2
e) 4 and 5

Which of the following is correctly described as a primary producer?
a) radiolarian
b) diatom
c) kinetoplastid
d) apicomplexan
e) oomycete

Which of the following statements concerning protists is true?
a) All slime molds have an amoeboid stage that may be followed by a stage during which spores are produced.
b) The primary organism that transmits malaria to humans by its bite is the tsetse fly.
c) Euglenozoans that are mixotrophic lack functional chloroplasts.
d) All protists have mitochondria, though in some species they are much reduced and known by different names.
e) All apicomplexans are autotrophic

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?
a) nucleomorphs
b) mitosomes
c) excavated feeding grooves
d) pseudopods
e) apical complex

Select the correct statement about photosynthesis by primary producers.
a) Photosynthetic protists and prokaryotes carry out the majority of the photosynthesis in aquatic communities.
b) Cyanobacteria carry out more of the world’s photosynthesis than protists do.
c) Land plants carry out over 80% of the world’s photosynthesis.

Which of the following are two groups that are adapted to anaerobic conditions and contain modified mitochondria that lack DNA?
a) dinoflagellates and diatoms
b) chlorophytes and radiolarians
c) apicomplexans and forams
d) gymnamoebas and slime molds
e) diplomonads and parabasalids

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 2
b) 2 and 3
c) 2 and 4
d) 4 and 5
e) 1 and 4

Which of the following statements concerning protists is true?
a) All protists have mitochondria, though in some species they are much reduced and known by different names.
b) The primary organism that transmits malaria to humans by its bite is the tsetse fly.
c) Euglenozoans that are mixotrophic lack functional chloroplasts.
d) All apicomplexans are autotrophic.
e) All slime molds have an amoeboid stage that may be followed by a stage during which spores are produced

A gelatinous seaweed that grows in shallow, cold water and undergoes heteromorphic alternation of generations is most probably what type of alga?
a) brown
b) red
c) green
d) yellow

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.

The primary treatment for giardiasis (infection with Giardia), as well as for trichomoniasis (infection with Trichomonas vaginalis) and for amoebic dysentery (infection with Entamoeba histolytica), is a drug marketed as Flagyl (generic name is metronidazole). The drug also kills anaerobic gut bacteria. Consequently, which of these are cues that Flagyl’s mode of action has nothing to do with attacking or disabling the parasites’ flagella, as the drug’s name might imply?
1. It would also harm the flagellated lining of the human intestine.
2. Entamoeba possesses pseudopods, not flagella, yet it is killed by Flagyl.
3. Prokaryotic flagella and eukaryotic flagella are radically different from each other and unlikely to be harmed by the same chemical.
4. Not all anaerobic gut bacteria possess flagella, yet it kills these bacteria
a) 2 and 3
b) 1 and 2
c) 2, 3, and 4
d) 1, 2, and 4
e) 1 and 3

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?
a) fossil
b) genetic
c) morphological
d) biochemical
e) ecological

If true, which of the following is the best evidence that the cyanelles are providing nutrition (in other words, calories) to the surrounding cercozoan?
a) If radiolabeled “heavy” water, 2H2O, enters the cyanelle and if, subsequently, radiolabeled oxygen appears in cercozoan cytosol.
b) If the cyanelle performs aerobic respiration.
c) If radiolabeled 14CO2 enters the cyanelle and if, subsequently, radiolabeled glucose is present in cercozoan cytosol.
d) If the cyanelle performs aerobic photosynthesis.
e) If the vesicle membrane that surrounds each cyanelle possesses glucose-transport proteins.

What must occur for asexual reproduction to be successful in P. chromatophora?
1. mitosis
2. S phase
3. meiosis
4. equal distribution of cyanelles during cytokinesis
a) 1 only
b) 2, 3, and 4
c) 1, 2, and 4
d) 1 and 2
e) 1, 2, and 3

A sign on the beach states, “Beach Closed. Red Tide.” The organisms interfering with your use of this beach are probably
a) amoebas
b) ciliates
c) diatoms
d) dinoflagellates
e) species of red algae

Which of the following pairs of protists and their characteristics is mismatched?
a) entamoebas-ingestive heterotrophs
b) golden algae-planktonic producers
c) apicomplexans-internal parasites
d) ciliates-red tide organisms
e) euglenozoans-unicellular flagellates

Which of the following statements about dinoflagellates is true?
a) All known varieties are autotrophic.
b) Many types lack mitochondria.
c) They possess two flagella.
d) Their dead cells accumulate on the seafloor, and are mined to serve as a filtering material.
e) Their walls are usually composed of silica plates

Which of the following is characteristic of ciliates?
a) Most live as solitary autotrophs in fresh water.
b) They use pseudopods as locomotory structures or as feeding structures.
c) They can exchange genetic material with other ciliates by the process of mitosis.
d) They are relatively specialized cells.
e) They are often multinucleate

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 diatom sperm cells locate diatom egg cells?
b) How do diatoms get transported from one location on the water’s 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 does carbon dioxide get into these protists with their glasslike valves?
e) How do diatoms with their glasslike valves avoid being shattered by the action of waves?

A large seaweed that floats freely on the surface of deep bodies of water would be expected to lack which of the following
a) gel-forming polysaccharides
b) bladders
c) thalli
d) holdfasts

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 ________

a) nucleus; bacterium
b) nucleus; archaean
c) mitochondrion; proteobacterium
d) chloroplast; cyanobacterium
e) mitochondrion; spirochete

Unlike most excavates, Giardia trophozoites have no oral groove and are unable to form food vacuoles. Thus, we should expect its nutrition (mostly glucose) to come from
a) endosymbiotic cyanobacteria.
b) the ventral disk by which it adheres to the intestinal lining.
c) plasma membrane proteins that are transporters or pumps.
d) its mitosomes.
e) osmosis involving aquaporins

Many types of foraminiferans form a symbiotic relationship with
a) algae
b) bacteria
c) seaweed
d) fungi
e) amoebas

Reinforced, threadlike pseudopods that can perform phagocytosis are generally characteristic of which group?
a) amoeboid stage of cellular slime molds
b) radiolarians and forams
c) entamoebas
d) oomycetes
e) gymnamoebas

A snail-like, coiled, porous test (shell) of calcium carbonate is characteristic of which group?
a) foraminiferans
b) gymnamoebas
c) diatoms
d) radiolarians

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?
a) It would be paraphyletic.
b) It would be monophyletic.
c) It would include all eukaryotes.
d) It would be polyphyletic

Which of the following is true of secondary endosymbiosis?
a) It is indicated by the presence of a double membrane surrounding the endymbiont.
b) An organism containing one endosymbiont engulfs another organism, and that organism becomes an endosymbiont.
c) It is indicated by the presence of a nucleomorph.
d) An organism containing an endosymbiont is engulfed by another organism and becomes an endosymbiont.
e) It is indicated by the presence of a mixotroph

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 most common pesticide used to kill Anopheles mosquitoes.
b) insert genes from a Plasmodium-resistant strain of mosquito into Anopheles mosquitoes.
c) use a “cocktail” of at least three different pesticides against Anopheles mosquitoes.
d) introduce a predator of the malarial parasite into infected humans.
e) increase the dosage of the least-expensive antimalarial drug administered to humans

What advantage do organisms that reproduce sexually have over organisms that reproduce asexually?
a) Their offspring are bigger and better able to reproduce.
b) Their offspring may be more adaptable to changes in the environment.
c) Their offspring can exist in both haploid and diploid stages.
d) Their offspring may have more mutations.

Which term describes the fusion of two gametes to form a diploid zygote?
a) Meiosis
b) Alternation of generations
c) Syngamy
d) Mitosis

Which term describes the multicellular haploid form of a protist that shows alternation of generations?
a) Spore
b) Zygote
c) Sporophyte
d) Gametophyte

Which structure mediates the attachment of spores to a surface on which to grow?
a) Flagella
b) Chloroplast
c) Holdfast
d) Sporophyte

Which of the following statements about Ulva’s haploid stage is true?
a) Haploid cells are produced by meiosis of diploid cells.
b) Haploid cells produce gametes by meiosis.
c) Gametes of the same mating type fuse to produce a diploid zygote.
d) The haploid Ulva cells are genetically identical to their diploid parents

How does the haploid form of Ulva “switch” to its diploid form?
a) Gametophytes produce cells that undergo meiosis and produce spores that germinate into diploid adults.
b) Gametophytes produce cells that undergo mitosis to produce gametes that fuse to form a zygote.
c) Sporophytes produce cells that undergo mitosis to produce gametes that fuse to form a zygote.
d) Sporophytes undergo meiosis to produce spores that germinate into diploid adults

True or false? Organisms that exhibit alternation of generations reproduce sexually in the diploid stage

Archaeplastids, which include red and green algae and land plants, are thought to have descended from a heterotrophic protist that engulfed a(n)
a) slime mold
b) alpha proteobacterium
c) cyanobacterium
d) apicomplexan
e) archaean extremophile

The chloroplasts of all of the following are thought to be derived from ancestral red algae, except those of
a) dinoflagellates.
b) diatoms.
c) green algae.
d) golden algae.
e) brown algae

A biologist discovers an alga that is marine, multicellular, and lives at a depth reached only by blue light. This alga probably belongs to which group?
a) golden algae
b) red algae
c) brown algae
d) dinoflagellates
e) green algae

Green algae differ from land plants in that many green algae
a) are unicellular.
b) have cell walls containing cellulose.
c) have alternation of generations.
d) have plastids.
e) are heterotrophs

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?
a) It will more accurately depict evolutionary relationships than does the current taxonomy.
b) It will be polyphyletic.
c) It will be monophyletic.
d) It will be a true clade.
e) It will be paraphyletic

_____ are eukaryotic autotrophs that float near the surface of water and are the basis of the food chain
a) Zooplankton
b) Slime molds
c) Phytoplankton
d) Cyanobacteria
e) Symbionts

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?
a) Dinoflagellates protect the corals from UV radiation.
b) Dinoflagellates protect the corals from pathogenic bacteria.
c) Dinoflagellates provide nutrients from the products of photosynthesis to the corals in exchange for a safe place to live.
d) Dinoflagellates attract zooplankton and other prey that the corals eat.
e) Dinoflagellates secrete the calcium carbonate that forms the “exoskeleton” of coral animals.

Plastids that are surrounded by more than two membranes are evidence of
a) origin of the plastids from archaea.
b) fusion of plastids.
c) evolution from mitochondria.
d) secondary endosymbiosis.
e) budding of the plastids from the nuclear envelope

Biologists suspect that endosymbiosis gave rise to mitochon-dria before plastids partly because
a) mitochondrial proteins are synthesized on cytosolic ribo-somes, whereas plastids utilize their own ribosomes.
b) the products of photosynthesis could not be metabolized without mitochondrial enzymes.
c) mitochondrial DNA is less similar to prokaryotic DNA than is plastid DNA.
d) without mitochondrial production, photosynthesis could not occur.
e) all eukaryotes have mitochondria (or their remnants), whereas many eukaryotes do not have plastids.

Which group is incorrectly paired with its description?
a) diplomonads-protists with modified mitochondria
b) diatoms-important producers in aquatic communities
c) apicomplexans-parasites with intricate life cycles
d) rhizarians-morphologically diverse group defined by DNA similarities
e) red algae-acquired plastids by secondary endosymbiosis

Which protists are in the same eukaryotic supergroup as land plants?
a) brown algae
b) dinoflagellates
c) green algae
d) red algae
e) both red algae and green algae

In life cycles with an alternation of generations, multicellular haploid forms alternate with
a) multicellular diploid forms.
b) unicellular haploid forms.
c) unicellular diploid forms.
d) multicellular haploid forms.
e) multicellular polyploid forms

Why has the kingdom Protista been abandoned?
a) Some protists are multicellular.
b) The kingdom Protista is polyphyletic.
c) Some protists are more closely related to plants, animals, or fungi than they are to other protists.
d) Some protists are as small as prokaryotes.
e) The second and third answers are correct.

Which group of organisms (ciliates, animals, or plants) has the most complex cells?
a) Ciliates
b) Plants
c) Animals

Which of the following statements supports the hypothesis of an endosymbiotic origin of mitochondria?
a) Diplomonads have modified mitochondria called mitosomes.
b) Some algae contain plastids surrounded by four membranes.
c) Each mitochondrion has its own DNA molecule

Which of the features below are found in all protist lineages?
a) Organelles that arose by secondary endosymbiosis.
b) Plastids
c) Mitochondria