Exam 3
Which of those below is NOT an important consideration when designing a fusion protein construct? A) Avoid hybridization of the fusion gene in the artificial construct. B) Reading frame is the same for both the fusion gene and reporter gene. C) Transcriptional start and stop signals are shared. D) Translational start and stop signals are shared.
A) Avoid hybridization of the fusion gene in the artificial construct.
25) It is believed that phototrophy arose approximately 3.3 billion years ago in A) Bacteria. B) Archaea. C) Eukarya. D) LUCA.
A) Bacteria
Which of the following terms is used to describe a synthetic DNA fragment? A) DNA cassette B) DNA hybrid C) recombinant DNA D) artificial chromosome
A) DNA cassette
The enzyme that covalently links both strands of a vector and inserted DNA in molecular cloning is A) DNA ligase. B) DNA phosphatase. C) DNA hydrolase. D) DNA transferase.
A) DNA ligase.
8) Which of the following is an assumption used in the molecular clock approach? A) Nucleotide changes accumulate in a sequence in proportion to time. B) Nucleotide changes are generally NOT transferred to progeny. C) Nucleotide changes are NOT random. D) Nucleotide changes are subject to intense selective pressure.
A) Nucleotide changes accumulate in a sequence in proportion to time.
40) The first catalytic and self-replication biological molecule was most likely\ A) RNA. B) DNA. C) proteins. D) ATP.
A) RNA.
One of the more formidable obstacles to mammalian gene cloning is the presence of A) introns. B) exons. C) repressors. D) integrators.
A) introns.
Expression vectors are designed to ensure that ________ can be efficiently ________. A) mRNA / transcribed B) DNA / transcribed C) mRNA / translated D) DNA / translated
A) mRNA / transcribed
19) Both deletions and insertions occur during the evolution of microbial genomes. Insertions bring in new genes that may be useful for the cell. Deletions A) may increase fitness of a microorganism by eliminating unneeded genes. B) always result in a severe loss of fitness for the microorganism. C) are uncommon because they are usually lethal. D) always result in a severe loss of fitness but keep microbial genomes compact.
A) may increase fitness of a microorganism by eliminating unneeded genes
22) Which is NOT a characteristic of a ʺprimitiveʺ state of microbial evolution? A) hyperthermophilic B) aerobic metabolism C) small genome D) branching near the root of the evolutionary tree of life
B) aerobic metabolism
2) What two gases were most abundant on early Earth? A) O2 and CO2 B) N2 and H2 C) CO2 and H2 D) CO2 and N2
C) CO2 and H2
39) ________ formed the semipermeable membrane-like surfaces for the earliest life forms. A) Proteins B) Hydrogen sulfide C) Lipid bilayers D) RNA
C) Lipid bilayers
) Some proteins expressed at high levels form inclusions that are relatively insoluble. What is the most effective way to facilitate purification of these proteins? A) Use a reporter gene to locate the inclusion. B) Decrease the number of insertions in the vector. C) Produce the protein as a fusion protein. D) Switch to an expression host with a larger intracellular volume.
C) Produce the protein as a fusion protein.
9) An important molecule in sequence-based evolutionary analyses of microbes are ________ genes. A) ATPase B) electron transport C) SSU rRNA D) tRNA
C) SSU rRNA
4) The earliest RNA probably functioned in A) catalysis. B) self-replication. C) both catalysis and self-replication. D) neither catalysis nor self-replication
C) both catalysis and self-replication.
15) Molecular sequencing suggests that mitochondria arose from a group of prokaryotic organisms within the A) Crenarchaeota. B) cyanobacteria. C) iron-oxidizing bacteria. D) Alphaproteobacteria.
D) Alphaproteobacteria.
Which of the following sequences is a palindrome, characteristic of many recognition sequences for restriction endonucleases? A) TTGCCGA AACGGCT B) GGGGGGG CCCCCCCC C) GTAATG CATTAC D) GAATTC CTTAAG
D) GAATTC CTTAAG
17) Two tubes are inoculated from the same tube containing a bacterial culture. The cultures are then transferred every day for 2 months. All of the media and growth conditions are the same in every tube. After 2 months of cultivation, the fitness and genotype frequencies of the populations in the two tubes are compared. The fitness of the two cultures is the same, but the genotype frequencies are very different in the two cultures. How is this possible? A) Two months is not long enough for different fitness levels to evolve even if the genotype frequencies change. B) This result is not possible because different genotype frequencies would result in different fitness levels under the same growth conditions. C) Natural selection caused the evolution of different genotype frequencies within the separate test tubes. D) Genetic drift within the small populations in the test tubes resulted in different genotype frequencies.
D) Genetic drift within the small populations in the test tubes resulted in different genotype frequencies.
23) Because DNA-DNA hybridization reveals subtle differences in genes, it is useful for differentiating organisms from different A) domains. B) families. C) orders. D) strains or species.
D) strains or species.
Members of the ________ are particularly abundant in the oceans, chemoorganotrophic, rarely pathogenic, and often produce pigments when grown on complex media. A) Clostridiales B) Flavobacteriales C) Pelagibacterales D) Rhizobiales
Flavobacteriales
What is unusual about phage MS2 infection of Escherichia coli? A) All proteins are synthesized simultaneously during infection so there are no early and late proteins. B) It attaches to the hostʹs pilus rather than the cellʹs surface. C) It enters through a host cell porin. D) More than one MS2 phage can be present in an individual E. coli cell.
It attaches to the hostʹs pilus rather than the cellʹs surface.
Which bacillus-shaped genus are primarily intracellular parasites of arthropods such as crustaceans and insects? A) Coxiella B) Klebsiella C) Roseospirillum D) Wolbachia
Wolbachia
Which of the following are the hosts for most enveloped viruses? A) Bacteria B) animals C) Archaea D) fungi
animals
The term ʺphageʺ is generally reserved for the viruses that infect A) animals. B) plants. C) bacteria. D) multiple species.
bacteria
What are the two main groups of green algae? A) chlorophytes and chrysophytes B) chlorophytes and charophyceans C) chrysophytes and charophyceans D) chlorarachniophytes and chlorophytes
chlorophytes and charophyceans
Endolithic phototrophic communities are most commonly found in ________ environments. A) dry B) hot C) humid D) windy
dry
The size and shape of viral particles is largely governed by the size and packaging of the viral A) envelope. B) enzymes. C) prophage. D) genome.
genome
The T4 bacteriophage could not infect Staphylococcus aureus because this bacterium does NOT possess a A) lipopolysaccharide outer membrane. B) teichoic acid outer membrane. C) pili. D) flagella.
lipopolysaccharide outer membrane
The amoebozoa use what structures for movement and feeding? A) threadlike pseudopodia B) cilia C) flagella D) lobe-shaped pseudopodia
lobe-shaped pseudopodia
Which group of eukaryotes LACKS alveoli? A) apicomplexans B) ciliates C) dinoflagellates D) oomycetes
oomycetes
A cell that allows the complete replication cycle of a virus to take place is said to be a A) permissive host. B) viral cell. C) dead cell. D) lytic cell.
permissive host
A pink-pigmented facultative methylotrophic bacterium is LEAST likely to be classified as a member of A) Rhizobiales. B) Rhodobacter. C) Methylobacterium. D) Proteobacteria.
rhodobacter
Early and late viral proteins are classified according to their relative A) evolutionary appearance in virus genomes. B) stability during infection. C) time of synthesis following host infection. D) transmission into virions.
time of synthesis following host infection.
The use of ________ is the easiest and most effective way of studying many animal and plant viruses. A) bacterial cultures B) tissue or cell culture C) live hosts D) prophages
tissue or cell culture
The concentration of infectious plaque forming units (pfu) per volume of fluid is known as the A) infectivity. B) virulence. C) titer. D) fluid infectivity.
titer
Which of the following conditions favors a lysogenic life cycle in bacteriophages? A) Having ssDNA. B) Having ssRNA. C) A lack of host bacteria. D) The presence of abundant hosts.
A lack of host bacteria.
Which objective would be best to use a Southern blot rather than a Northern blot? A) Determine if a gene is present in a genome. B) Discover gene function. C) Identify regulatory gene-protein interactions. D) Quantify expression profiles of a gene.
A) Determine if a gene is present in a genome.
What is the first step in constructing a metagenomic library from RNA? A) The RNA must be converted to cDNA. B) The RNA must be amplified through PCR, producing many RNA copies. C) The RNA must be screened to identify the genes of interest. D) The RNA must be inserted into plasmid vectors. What is the first step in constructing a metagenomic library from RNA?
A) The RNA must be converted to cDNA.
Which statement is TRUE? A) YACs are more likely than BACs to undergo recombination and rearrangement. B) BACs are more likely than YACs to undergo recombination and rearrangement. C) YACs and BACs undergo recombination and rearrangement at about the same rate. D) It is impossible to state with any certainty whether YACs or BACs are more likely to undergo recombination and rearrangement, because environmental factors play a major role in the probability of one or the other occurring.
A) YACs are more likely than BACs to undergo recombination and rearrangement
The principle behind nucleic acid probe design is that the probe itself must contain A) a key complementary part of the target gene sequence of interest. B) all of the nucleotide sequence of the gene of interest to conclusively identify the gene. C) an antibody to specifically bind to the gene of interest. D) at least three separate complementary regions of the gene of interest.
A) a key complementary part of the target gene sequence of interest.
Inserting a kanamycin resistance cassette into a catabolic operon to confirm the gene is essential in degradation of a particular compound would involve all of the following EXCEPT A) a reporter gene. B) ligation. C) recombination. D) transformation.
A) a reporter gene.
To verify a gene was cloned into a vector successfully, sequencing the vector as well as ________ are commonly performed. A) agarose gel electrophoresis B) fluorescence in situ hybridization C) protein purification D) northern blots
A) agarose gel electrophoresis
11) A gene for a specific trait may have more than one form, allowing the trait to vary. These sequence variants of a gene are called a(n) A) alleles. B) MLST. C) horizontal gene transfers. D) ribotypes.
A) alleles.
1) The earliest stromatolites were probably formed by A) anoxygenic phototrophs. B) anoxygenic lithotrophs. C) oxygenic phototrophs. D) oxygenic lithotrophs
A) anoxygenic phototrophs.
27) You are studying 12 new isolates from the human skin. Their average nucleotide identity for shared orthologous genes is 97%. The isolates would most likely be A) classified as individual strains of the same species. B) classified as individual species of the same genus. C) split into different families. D) classified as the same species if they can mate via conjugation.
A) classified as individual strains of the same species.
3) Compared with today, the temperature on Earth during its first half-billion years was probably A) considerably warmer. B) considerably colder. C) about the same as today. D) about the same as today on average, but the diurnal fluctuations were much greater.
A) considerably warmer.
10) A monophyletic group is a group that A) descended from one ancestor. B) has the same fitness level. C) possesses one taxonomic trait that is the same. D) shares one phylogenetic marker.
A) descended from one ancestor.
At which time period(s) during PCR thermocycling is/are hottest in temperature? A) during DNA denaturation B) during primer annealing C) during primer extension/elongation D) Both the first and last cycles are hotter in temperature than all other cycles.
A) during DNA denaturation
What molecular mechanism/feature does site-directed mutagenesis exploit to introduce a mutation at a specific site? A) flanking complementary bound nucleotides permit non-complementary base pairing B) methylated nucleotides disrupt DNA polymeraseʹs proofreading C) nucleotide substitution when one is depleted D) transposase-induced base pair changes
A) flanking complementary bound nucleotides permit non-complementary base pairing
) Which of those listed below is LEAST similar in what is being studied and concluded? A) fluorescence in situ hybridization B) GFP fusion protein C) Northern blot D) RT-PCR
A) fluorescence in situ hybridization
It is possible to rapidly screen for mutations in regulatory genes using A) gene fusions. B) defective proteases. C) microinjection. D) Southern blotting.
A) gene fusions.
If a foreign gene is cloned into an expression host, it is important that the host itself A) not produce the protein being studied. B) produce the protein in larger amounts than the vector. C) repress the genetic expression being studied. D) produce signal proteins to tag the host protein.
A) not produce the protein being studied.
34) As oxygen appeared in the atmosphere, ________ also accumulated, which formed a protective barrier that protects the Earth from ________. A) ozone / UV radiation B) elemental sulfur / volcanism C) ferrous iron / hydroxylating radicals D) sulfate / hydrogen sulfide
A) ozone / UV radiation
12) A key concept in evolution is that all mutations are A) random. B) neutral. C) deleterious. D) either deleterious or beneficial.
A) random
13) LUCA is A) the last universal common ancestor. B) the individual ancestor of each of the three domains. C) actually somewhat of a misnomer because it is now believed that each of the domains arose independently. D) All of the answers are correct
A) the last universal common ancestor.
44) Systematic analysis now commonly includes ________ to identify, characterize, and determine relationships between new strains of bacterial species. A) whole genome analysis B) microscopy C) staining D) pigments
A) whole genome analysis
How can the amebozoans and radiolarians be distinguished from each other with microscopy? A) Amebozoans have lobe-shaped pseudopodia, and radiolarians have threadlike pseudopodia, and radiolarians have radial symmetry. B) Amebozoans have lobe-shaped pseudopodia, amebozoans have radial symmetry, and radiolarians have unusually large, thick pseudopodia. C) Amebozoans have large but thin pseudopodia and radiolarians have thick, lobe-shaped pseudopodia. D) Amebozoans have radial symmetry and threadlike pseudopodia, whereas radiolarians have lobe-shaped pseudopodia.
Amebozoans have lobe-shaped pseudopodia, and radiolarians have threadlike pseudopodia, and radiolarians have radial symmetry
Spindle-shaped viruses have been shown to infect only A) Eukarya. B) Bacteria. C) Archaea. D) plants.
Archaea.
Unusually shaped viruses, such as lemon-shaped and spindle-shaped, have recently been discovered in A) Archaea. B) Bacteria. C) Archaea and Bacteria. D) Eukarya.
Archaea.
Which of the following is NOT a limitation to using auxotrophs to prevent the spread of genetically modified genes to wild populations? A) Auxotrophs may mutate in ways that allow them to synthesize the limiting nutrient. B) Auxotrophs self-destruct using self-toxins when this method is applied. C) Auxotrophs often cross-feed from the metabolites of other organisms in the environment. D) Back mutation to the wild type may occur.
B) Auxotrophs self-destruct using self-toxins when this method is applied.
Which of the following is NOT a common step in molecular cloning using plasmids? A) Fragment DNA into small segments. B) Hybridize DNA sequences with slightly mismatched oligonucleotides. C) Ligate DNA into vectors. D) Insert the vectors into a host.
B) Hybridize DNA sequences with slightly mismatched
31) Based on the phylogenetic tree below, which of the following statements is FALSE? A) Species E is more closely related to species A than to species D. B) Species D is more closely related to species C than to species E. C) Species F is more closely related to species D than to species E. D) Species C is more closely related to species B than to species D.
B) Species D is more closely related to species C than to species E.
Cosmids are a type of A) bacterial artificial chromosomes (BACs). B) cloning vector. C) heat stable polymerase. D) RNA/DNA hybrid.
B) cloning vector.
32) The early energy reactions used hydrogen, which is a powerful A) oxidant. B) electron donor. C) electron acceptor. D) stabilizer.
B) electron donor
29) Microbial ________ studies the diversity of microorganisms and links their phylogeny with ________. A) taxonomy / genotype B) phylogeny / phenotype C) taxonomy / phenotype D) systematics / taxonomy
B) elemental sulfur
28) The pan genome of a microbial species is constantly changing because of A) bottleneck events. B) horizontal gene transfer. C) substitutions. D) substitution and bottleneck events.
B) horizontal gene transfer.
43) Multilocus sequence typing (MLST) involves sequencing several different A) genomes. B) housekeeping genes. C) tRNA genes. D) rRNA genes.
B) housekeeping genes.
If a protein that could be toxic to the expression host needs to be expressed in large quantities, then it is best to select an expression vector that A) is not able to be replicated. B) is inducible. C) is attached to a normal cell promoter. D) allows continual expression of the protein.
B) is inducible.
35) Two eukaryotic organelles that are hypothesized to be the result of endosymbiosis are the ________ and the ________. A) nucleus / Golgi body B) mitochondrion / chloroplast C) endoplasmic reticulum / Golgi body D) hydrogenosome / chloroplast
B) mitochondrion / chloroplast
) Polyvalent vaccines using vaccinia virus are highly favored by doctors and physicians but are especially challenging for those who develop them, because A) coat proteins form a relatively rigid structure and do not allow much space for additional proteins to be expressed. B) multiple foreign proteins simultaneously synthesized often disrupts each otherʹs activity. C) vaccinia and most other viruses engineered for vaccines contain only one restriction site for cloning in their genome. D) virus genetic manipulation uses transfection, which is an inherently inefficient process.
B) multiple foreign proteins simultaneously synthesized often disrupts each otherʹs activity.
41) The evolutionary history of a group of organisms is called its ________ and it is inferred from ________. A) taxonomy / phenotype B) phylogeny / nucleotide sequence data C) phylogeny / phenotype D) taxonomy / morphology
B) phylogeny / nucleotide sequence data
) To estimate the total concentration of a beneficial bacterial species in yogurt, ________ would provide the quickest results. A) fluorescence in situ hybridization B) qPCR C) RT-PCR D) a Southern blot
B) qPCR
The principle underlying how salmon were genetically engineered to grow faster is the A) removal of a gene responsible for feeling full after eating. B) replacement of inducible to constitutive hormone production. C) resistance to bacterial infections which waste metabolic energy in the salmon to fight off. D) addition of genes to enhance blood circulation and tissue development.
B) replacement of inducible to constitutive hormone production.
Cells that have "insertional inactivation" of the lacZ gene are A) blue. B) white. C) yellow. D) fluorescent green.
B) white.
Members of the ________ are the most abundant bacteria present in the large intestine of humans and contain unusual ________ in their cell membranes. A) Bacteroides / glycerolipids B) Bacteroides / sphingolipids C) Sphingobium / glycerolipids D) Sphingobium / sphingolipids
Bacteroides / sphingolipids
16) Which statement most closely expresses our present understanding? A) The chloroplast is an ancestor of the cyanobacteria. B) The cyanobacteria are descendents of the chloroplast. C) The chloroplast arose from the incorporation of a cyanobacterial-like organism. D) The chloroplast and the cyanobacteria are not closely (or specifically) related.
C) The chloroplast arose from the incorporation of a cyanobacterial-like organism.
36) Microbial species have a core genome and a pan genome. What is the difference between the two ? A) The core genome consists of all the nucleic acid polymerases and translation enzymes, while the pan genome consists of all the biosynthetic pathways. B) The core genome is the set of genes within the mitochondria, while the pan genome is the set of genes in the nucleus of a species. C) The core genome is a set of genes shared by all members of a species, while the pan genome includes the core genes as well as genes that are not shared by all members. D) The core genome is the set of genes introduced by horizontal gene transfer, while the pan genome is the set of genes that is not transferred horizontally.
C) The core genome is a set of genes shared by all members of a species, while the pan genome includes the core genes as well as genes that are not shared by all members.
14) Horizontal gene transfer A) is so rare over evolutionary history that it is not considered when examining microbial evolution. B) occurs within bacterial species. C) complicates the construction of phylogenetic trees and the interpretation of specific traits in relation to evolution. D) only affects the evolution of plasmids.
C) complicates the construction of phylogenetic trees and the interpretation of specific traits in relation to evolution.
Which of the following is NOT an example of synthetic biology? A) assembling gene sequences together into genome and creating a living organism from it B) creating a new metabolic pathway that produces a previously unidentified compound C) developing a novel polyvalent vaccine D) making Escherichia coli photographic
C) developing a novel polyvalent vaccine
18) If you allowed 10 identical parallel Salmonella cultures to evolve for 10,000 generations under new growth conditions with very little nitrogen, the parallel cultures would A) evolve identical adaptations to use the nitrogen source provided in the media. B) not change or adapt very much over this small number of generations. C) each accumulate different random mutations resulting in different adaptations to use the nitrogen in the media. D) direct mutations to occur in nitrogen utilization and uptake genes in order to adapt rapidly to the culture conditions.
C) each accumulate different random mutations resulting in different adaptations to use the nitrogen in the media.
33) Oxygen did not accumulate in the early atmosphere until it reacted with reduced materials, especially ________, in the oceans. A) hydrogen B) elemental sulfur C) ferrous iron D) nitrate
C) ferrous iron
What makes eukaryotic transcripts easier to isolate than bacterial transcripts? A) Eukaryotic transcripts are not methylated but their genes are often methylated. B) Larger transcript size in eukaryotes enables easy size-selection methods. C) mRNA is polyadenylated in eukaryotes. D) Transcripts are the most abundant RNAs in eukaryotes.
C) mRNA is polyadenylated in eukaryotes.
24) Which taxonomic tool would scientists use if they wanted to determine if an outbreak of food poisoning was caused by a particular strain of a pathogen? A) fluorescence in situ hybridization B) DNA-DNA hybridization C) multilocus sequence typing D) fatty acid methyl ester analysis
C) multilocus sequence typing
42) One widely used method of examining evolutionary relationships is ________, which is based on the assumption that evolution is most likely to have proceeded by the path requiring fewest changes. A) topology B) neighbor joining C) parsimony D) systematics
C) parsimony
The Ti plasmid is best suited for genetically manipulating A) Agrobacterium spp. B) fish. C) plants. D) viruses.
C) plants.
) Using a host defective in proteases is likely to be necessary when A) engineering a complete metabolic pathway requiring several different enzymes. B) overproducing proteins. C) producing a small protein. D) engineering transgenic animals with immune systems.
C) producing a small protein.
Which process results in the production of a hybrid polypeptide? A) vector fusion B) operon fusion C) protein fusion D) translational fusion
C) protein fusion
A(n) ________ gene is a gene that encodes a protein that is easy to detect and assay. A) encoder B) translational C) reporter D) recorder
C) reporter
Recognizing pathogens that contain multiple unique proteins which enable the human immune system to recognize just one and mount an effective response has opened the door on development of some vaccines only being A) attenuated carrier viruses. B) monovalent. C) subunit vaccines. D) purified protein administered.
C) subunit vaccines.
Which of the following is NOT a member of the Deltaproteobacteria? A) Campylobacter B) Desulfovibrio C) Geobacter D) Syntrophobacter
Campylobacter
Bacteria in the phylum ________ occur as elementary or reticulate bodies depending on their life cycle stage, are obligate intracellular parasites, and also have relatively small genomes. A) Bacteroidetes B) Chlamydiae C) Planctomycetes D) Rickettsia
Chlamydiae
Snapping division is a hallmark trait of ________ which can be visualized under a microscope by ________. A) Actinobacteria / two adjacent cells linked, appearing as an M dividing into four B) Actinobacteria / one cell appearing as a V dividing into two C) Coryneform bacteria / two adjacent cells linked, appearing as an M dividing into four D) Coryneform bacteria / one cell appearing as a V dividing into two
Coryneform bacteria / one cell appearing as a V dividing into two
Prophage formation occurs after lambda infection if A) the cI gene is transcribed and cI protein accumulates. B) cII expression occurs. C) Cro accumulates in the cell. D) both Cro and cI are equally activated.
Cro accumulates in the cell
5) Chemical reactions involving ________ have been proposed as energy-yielding reactions for the earliest organisms on Earth. A) Fe, O2, and H2 B) S, O2, and H2 C) S, and O2 D) S, and H2
D) S, and H2
38) Which of the following statements is FALSE concerning the universal tree of life? A) Previous versions of the universal tree of life were based largely on fossils and comparative biology, which overlooked the diversity of and relationships between most prokaryotes. B) The current universal tree of life is supported by multiple genes including SSU rRNA sequences. C) The current universal tree of life depicts three domains of life, two of which are prokaryotic. D) The current universal tree of life is based on molecular sequences and completely changes our view of evolutionary relationships between eukaryotic species.
D) The current universal tree of life is based on molecular sequences and completely changes our view of evolutionary relationships between eukaryotic species.
What is the most important advantage of Pfu polymerase over Taq polymerase? A) Unlike Taq polymerase, Pfu polymerase functions well at relatively high temperatures. B) It is from a bacterium, not an archaean, so it is more effective for replicating eukaryotic DNA. C) Pfu polymerase removes the need for primers during PCR. D) Unlike Taq polymerase, Pfu polymerase has proofreading activity.
D) Unlike Taq polymerase, Pfu polymerase has proofreading activity.
After digesting a DNA sequence, a restriction endonuclease can generate A) blunt ends. B) overhangs. C) sticky ends. D) blunt ends, overhangs, or sticky ends.
D) blunt ends, overhangs, or sticky ends.
21) Ribotyping A) bypasses sequencing and sequence alignments. B) exploits unique DNA restriction patterns. C) allows discrimination between species and different strains of a species. D) bypasses sequencing and sequence alignments, exploits unique DNA restriction patterns, and allows discrimination between species and different strains of a species.
D) bypasses sequencing and sequence alignments, exploits unique DNA restriction patterns, and allows discrimination between species and different strains of a species.
A poorly immunogenic vaccine often suggests the foreign proteins were not properly recognized by the immune system due to a lack of ________ necessary, which can also be engineered to occur with additional molecular manipulations. A) complex folding B) methylation C) glucosylation D) glycosylation
D) glycosylation
37) What characteristics make a gene a good candidate for determining the evolutionary relationships between organisms? A) highly conserved B) universally distributed C) transferred horizontally between species D) highly conserved and universally distributed
D) highly conserved and universally distributed
One challenge in cloning human somatotropin is that A) it consists of multiple polypeptides, making synthesis complex. B) its gene cannot be cloned as cDNA. C) it can only be expressed by eukaryotic cells. D) it is susceptible to digestion by bacterial proteases because it is a small protein hormone.
D) it is susceptible to digestion by bacterial proteases because it is a small protein hormone.
) Cloning vectors can be distinguished from expression vectors by A) carrying ori genes for replication of the cloned sequence. B) having a multiple cloning site (MCS). C) having a high copy number per cell. D) lacking a promoter site upstream of the insertion site.
D) lacking a promoter site upstream of the insertion site.
A polymerase chain reaction (PCR) copies an individual gene segment in vitro with a(n) ________ primer(s). A) individual RNA B) individual DNA C) pair of RNA D) pair of DNA
D) pair of DNA
20) Polyphasic taxonomy uses methods that include A) phenotypic methods. B) genotypic methods. C) phylogenetic methods. D) phenotypic, genotypic, and phylogenetic methods
D) phenotypic, genotypic, and phylogenetic methods
The genes encoding green fluorescent protein (GFP) and β-galactosidase are typically used in cloning as A) transcription regulators. B) global control genes. C) promoter sequences. D) reporter genes.
D) reporter genes.
6) Evolution is driven by A) random mutation. B) novel metabolic pathways. C) selection pressure. D) selection pressure applied to random mutation.
D) selection pressure applied to random mutation
26) The oxic atmosphere created conditions that led to the evolution of various new metabolic pathways, such as A) sulfide oxidation. B) nitrification. C) iron oxidation. D) sulfide oxidation, nitrification, and iron oxidation.
D) sulfide oxidation, nitrification, and iron oxidation.
7) Microorganisms were probably restricted to the oceans and subsurface environments until A) aquatic life brought them onto land. B) chemoorganotrophy developed. C) phototrophy evolved. D) the ozone layer was made.
D) the ozone layer was made.
The packaging mechanism of T4 DNA involves cutting of DNA from A) linear genetic elements. B) circular genetic elements. C) DNA concatemers. D) its host cells.
DNA concatemers
The hepadnavirus DNA polymerase acts as which of the following? A) DNA polymerase B) reverse transcriptase C) protein primer for synthesis of a strand of DNA D) DNA polymerase, reverse transcriptase, and protein primer for DNA synthesis
DNA polymerase, reverse transcriptase, and protein primer for DNA synthesis
How could overlapping genes in a positive ssDNA virus genome be predicted? A) Convert the positive ssDNA into its complementary ssDNA and search for genes in the negative ssDNA strand for sequences used in more than one predicted gene. B) Directly search the three frames of the positive ssDNA for genes that have sequences where more than one gene is predicted. C) Convert the positive ssDNA into negative ssDNA and search all six possible frames for genes that use part of the same sequence. D) Convert the positive ssDNA into its complementary ssDNA and search for genes in the negative ssDNA strand that also share a complementary gene in the positive strand.
Directly search the three frames of the positive ssDNA for genes that have sequences where more than one gene is predicted.
T4 genes are transcribed by host RNA polymerase, yet this transcription is carefully controlled so that groups of T4 genes are transcribed in a specific order after infection. How is this accomplished? A) Early T4 genes encode for proteolytic enzymes that destroy the host RNA polymerase. Subsequently a viral polymerase is created that transcribes the middle and late genes in the correct order. B) Early and middle T4 genes encode for RNA polymerase-modifying proteins so that only phage promoters are recognized. C) Each group of T4 genes has a different promoter that indicates the order in which they should be transcribed based on the affinity of the promoter for the host RNA polymerase. D) Rolling circle replication of the viral genome ensures that the genes are available for transcription in the correct order.
Early and middle T4 genes encode for RNA polymerase-modifying proteins so that only phage promoters are recognized
Campylobacter and Helicobacter are two genera within the ________ class of Proteobacteria. A) Alphaproteobacteria B) Betaproteobacteria C) Deltaproteobacteria D) Epsilonproteobacteria
Epsilonproteobacteria
Which of the following is NOT true of Epsilonproteobacteria? A) They include the genera Campylobacter and Helicobacter. B) Many species require relatively low O2 levels to grow. C) Epsilonproteobacteria are present in freshwater, marine systems, and terrestrial environments. D) Epsilonproteobacteria are prolific metal reducers.
Epsilonproteobacteria are prolific metal reducers
Biosynthesis of vitamin K (menaquinone) by ________ spp. inhabiting the ________ of humans is a potentially important mutualistic relationship for human health. A) Bifidobacterium / intestinal tract B) Bifidobacterium / stomach C) Escherichia / intestinal tract D) Escherichia / stomach
Escherichia / intestinal tract
What would most likely result if an exponentially growing culture of Lactobacillus spp. fermenting glucose was accidentally transferred into a highly aerated environment? A) Aerobic catabolism of glucose would begin rather than aerobic degradation, due to the presence of O2. B) Fermentation of glucose would continue, because the cells are insensitive to O2 despite lacking aerobic metabolism capabilities. C) The cells would halt their metabolism due to the presence of N2, which acts as a global repressor of fermentation in this group. D) The population would die due to the presence of O2, because it is a strict anaerobe.
Fermentation of glucose would continue, because the cells are insensitive to O2 despite lacking aerobic metabolism capabilities
What will happen if the Mu repressor is NOT synthesized? A) Genome replication will not be able to occur. B) It will lyse its host. C) Mu will improperly synthesize its capsid. D) Transposition will not be possible.
It will lyse its host.
A yogurt, which had ʺcontains live culturesʺ on its label, was transferred onto an acidic carbohydrate-containing medium for selective enrichment. Eventually, isolates of the ________ genus were obtained. A) Lactobacillus B) Leuconostoc C) Peptococcus D) Streptococcus
Lactobacillus
Which bacterial genus would be best to select for fermenting cabbage to make homemade sauerkraut? A) Clostridium B) Lactobacillus C) Propionibacterium D) Staphylococcus
Lactobacillus
Which of the following statements is FALSE? A) Lambda is a temperate phage that infects Escherichia coli. B) Lambda is a linear double-stranded DNA phage. C) Lambda is replicated by the rolling circle mechanism. D) Lambda always circularizes upon entering the host cell.
Lambda always circularizes upon entering the host cell
Which species does NOT produce endospores? A) Bacillus cereus B) Clostridium pasteurianum C) Listeria monocytogenes D) Paenibacillus popilliae
Listeria monocytogenes
Which of the following best distinguishes deltaproteobacteria from epsilonproteobacteria? A) Deltaproteobacteria are most commonly found at anoxic-oxic interfaces while epsilonbacteria are most commonly found in anoxic environements. B) Many epsilonbacteria oxidize sulfur compounds, which could be produced by a sulfur-reducing deltaproteobacterium. C) A sulfate-reducing epsilonbacterium produces sulfite, which a deltaproteobacterium reduces further to hydrogen sulfide. D) An epsilonbacterium reduces sulfur compounds whereas all deltaproteobacteria oxidize sulfur compounds.
Many epsilonbacteria oxidize sulfur compounds, which could be produced by a sulfur-reducing deltaproteobacterium
Of the phages listed below, which creates mutations in its host genome via transposition? A) lambda B) M13 C) Mu D) T7
Mu
Which bacterial genus is LEAST related to the others listed? A) Actinomyces B) Mycobacterium C) Nocardia D) Streptomyces
Mycobacterium
Which group in Bacteria lacks cell walls? A) Corynebacterium B) Mycoplasma C) Sporosarcina D) Tenericutes
Mycoplasma
What are the possible consequences of viral infection of an animal cell? A) rapid lysis or latent infections B) lysogeny followed by eventual lysis C) lysis or lysogeny D) Outcomes vary from rapid lysis to persistent infections, latent infections, or cancer.
Outcomes vary from rapid lysis to persistent infections, latent infections, or cancer
A gram-negative, nonsporulating rod that is highly motile, oxidase negative, facultatively aerobic, ferments glucose, and urease-positive is likely to be of which genus? A) Pseudomonas B) Proteus C) Lactobacillus D) Rickettsia
Proteus
Which type of viruses generally has the smallest genome? A) bacteriophages B) DNA viruses C) RNA viruses D) viroids
RNA viruses
Which statement is TRUE? A) All viruses contain their own nucleic acid polymerases. B) RNA viruses contain their own nucleic acid polymerases. C) Viruses do not contain their own nucleic acid polymerases. D) The origins of the nucleic acid polymerases used by viruses are eukaryotic.
RNA viruses contain their own nucleic acid polymerases
If the hypothesis stating viruses evolved prior to living organisms on Earth is TRUE, the first type of viruses in the world were likely A) bacteriophages. B) DNA viruses. C) retroviruses. D) RNA viruses.
RNA viruses.
Reverse transcriptase is a(n) A) RNA-dependent DNA polymerase. B) DNA-dependent DNA polymerase. C) RNA-dependent RNA polymerase. D) DNA-dependent RNA polymerase.
RNA-dependent DNA polymerase
Ascospores are produced in all of the following taxa EXCEPT A) Aspergillus. B) Candida. C) Rhizopus. D) Saccharomyces.
Rhizopus
Spoilage of bread, which appears dark green-blue to black in color, is most likely caused by the fungus A) Aspergillus niger. B) Batrachochytrium dendrobatidis. C) Glomus spp. D) Rhizopus nigricans.
Rhizopus nigricans
Which genus is most easily distinguishable from others below by occurring in cell clusters of 8 or more? A) Peptostreptococcus B) Sarcina C) Staphylococcus D) Streptococcus
Sarcina
Which taxon is NOT gram-positive? A) Actinobacteria B) Firmicutes C) Sphingobacteria D) Streptococcus
Sphingobacteria
A moistened swab rubbed onto a personʹs forearm then onto a nutrient agar plate with 7.5% NaCl would most likely result in the isolation of ________ spp. A) Clostridium B) Halobacterium C) Sarcina D) Staphylococcus
Staphylococcus
A soil sample was diluted into a nutrient broth, then spread onto a plate and grown for one week at room temperature. Several colonies appeared dusty or fuzzy and yet were identified as bacteria—not as fungi. Which genus do these isolates likely belong in? A) Actinomyces B) Mycobacterium C) Nocardia D) Streptomyces
Streptomyces
What would be the consequence of deleting the late T4 genes? A) The T4 genome would not be copied. B) T4 mRNA would not be produced. C) T4 capsid proteins would not be made. D) ATP would not be produced and the T4 genome would not be packaged into the capsid.
T4 capsid proteins would not be made
How are T7 genes transcribed? A) Host RNA polymerase is modified to recognize the T7 promoter. B) Host RNA polymerase directly translates the T7 genes. C) T7 has its own RNA polymerase, which is packaged in its capsid and injected into the host during infection to transcribe T7 genes. D) T7 has its own RNA polymerase, which must first be synthesized by the host.
T7 has its own RNA polymerase, which must first be synthesized by the host.
The general steps of the viral lifecycle are similar in most viruses. One major exception, however, is entry into the host cell. How does this step differ between an animal cell and E coli? A) The entire virion is taken into an animal cell, but only the viral genome enters E coli. B) The entire virion enters E coli, but only the nucleic acid is taken up by animal cells. C) The virion fuses to the bacterial cell membrane of E coli, while the genome is injected into an animal cell. D) The virion randomly attaches to E coli, but viral binding to a specific receptor is required for entry into animal cells.
The entire virion is taken into an animal cell, but only the viral genome enters E coli.
In E. coli, the adenine in the sequence GATC is methylated by the Dam enzyme. In the same cells, a restriction endonuclease recognizes and cleaves dsDNA with the sequence GATC on either strand. Why does E. coli have these two enzymes? A) The enzymes cut the E. coli genome into pieces that bind to viral particles and inhibit viral replication. B) The enzymes increase the rate of mutation and genome rearrangement, thus increasing the likelihood that E. coli cells will mutate and become resistant to viral infection. C) The enzymes encourage lysogeny because the cleavage sites are recognized by viral integrases. D) The enzymes protect E. coli from infection by preferentially degrading viral or other exogenous DNA that is not methylated.
The enzymes protect E. coli from infection by preferentially degrading viral or other exogenous DNA that is not methylated.
You isolate a bacteriophage that can replicate in E. coli. Through chemical analyses you determine that the only nucleic acid present is RNA. You isolate the RNA and put it in a test tube with all of the enzymes, amino acids, and RNAs necessary for translation. The RNA is translated directly, without being copied into a complementary strand first, and new infectious virions are made and released. What does this tell you about the bacteriophage? A) The viral genome is ssRNA of the plus sense. B) The viral genome is ssRNA of the minus sense. C) The bacteriophage is a retrovirus. D) The bacteriophage is probably a new strain and should be studied further.
The viral genome is ssRNA of the plus sense
Despite ether-linked lipids being a hallmark of the Archaea, the thermophilic sulfate-reducing bacteria in ________ also contain ether-linked lipids, which suggests they may be more closely related to Archaea than many other groups in Bacteria. A) Aquifex B) Thermodesulfobacterium C) Thermus D) Verrucomicrobium
Thermodesulfobacterium
Which of the following is LEAST commonly associated with endospore-forming bacteria? A) They are coccus-shaped organisms. B) They are primarily soil dwellers. C) They can survive adverse environmental conditions. D) They are saprophytic.
They are coccus-shaped organisms
How do reoviruses increase the translational activity of human ribosomes so that they can rapidly produce viral proteins during infection? A) They chemically modify the RNA transcripts with methyl caps in a similar manner to normal eukaryotic RNA processing. B) They keep a ribosome binding site specific to human ribosomes on their genome. C) They have introns and sometimes extons in their genomes to make their RNA resemble eukaryotic mRNA. D) They only adhere to and infect metabolically active host cells where protein synthesis is high.
They chemically modify the RNA transcripts with methyl caps in a similar manner to normal eukaryotic RNA processing.
Which of the following is NOT a trait of rickettsias? A) They are obligate intracellular parasites. B) They lack cell walls. C) They have not been cultivated in the absence of host cells. D) Both the host and parasite are required in order to be alive and metabolically active.
They lack cell walls
Which of the following organisms is most likely to form a relationship with Syntrophobacter wolinii? A) a bacterium that oxidizes acetate B) a bacterium that consumes sulfate C) a bacterium that consumes H2 D) a bacterium that consumes pyruvate
a bacterium that consumes H2
Restriction is A) the viral process whereby a hostʹs DNA ceases normal functioning. B) the viral process whereby the virus prevents other viruses from entering the cell. C) a general host mechanism to prevent the invasion of foreign nucleic acid. D) a general host mechanism to prevent virus particles from further infective action.
a general host mechanism to prevent the invasion of foreign nucleic acid
For a pure culture of Saccharomyces cerevisiae cells that were all derived from a single cell to mate A) a mating-type switch in one or more cells in the culture must occur. B) both the α and the a gene must be fully expressed in the initial population. C) the α gene must be fully repressed in the population. D) some cells must exist as diploids.
a mating-type switch in one or more cells in the culture must occur
Which of the following traits is NOT a characteristic of Caulobacter? A) abundant in aquatic habitats rich in nutrients B) produces a cytoplasmic outgrowth (prostheca) C) aerobic chemoorganotrophs D) asymmetric cell division
abundant in aquatic habitats rich in nutrients
Due to the presence of mycolic acids in the cell wall of Mycobacterium spp., the ________ staining procedure can be used as a diagnostic tool to identify this genus. A) acid-fast B) DAPI C) Gram D) lipo
acid-fast
The unconventional dsDNA genome replication mechanism where no lagging strand exists is a hallmark of which group of viruses? A) adenoviruses B) coronaviruses C) herpes viruses D) pox viruses
adenoviruses
A prophage replicates A) along with its host while the lytic genes are expressed. B) along with its host while the lytic genes are not expressed. C) independently of its host while the lytic genes are expressed. D) independently of its host while the lytic genes are not expressed.
along with its host while lytic genes are not expressed
When two different influenza viruses infect the same cell, their segmented genomes can undergo reassortment which will result in A) antigenic drift. B) antigenic shift. C) loss of neuramidase. D) loss of hemagglutinin.
antigenic shift.
All viral particles A) are metabolically inert. B) are smaller than bacterial cells. C) contain an envelope to prevent its degradation outside of a host. D) exhibit cell lysis under a particular condition.
are metabolically inert
The filamentous DNA phages are unusual, because they A) are released from the host without the host being lysed. B) have linear genomes. C) replicate without a host. D) are released from the host without being lysed and have linear genomes.
are released from the host without the host being lysed.
Which statement is TRUE regarding fungal spores? A) Conidia and ascospores are sexual spores. B) Ascospores and basidiospores are asexual spores. C) Basidiospores and conidia are sexual spores. D) Ascospores and basidiospores are sexual spores.
ascospores and basidiospores are sexual spores
For bacteriophages and animal viruses ________ is the step in the viral life cycle that determines host cell specificity. A) attachment B) penetration C) synthesis D) assembly
attachment
Blocking polyomavirus SV40ʹs ability to integrate its genome into host cells would A) avoid cancer development caused by the virus. B) increase the rate of transformation. C) increase the latent period of SV40. D) switch SV40 into a lytic lifecycle which would be especially harmful to the host cells.
avoid cancer development caused by the virus.
In T7, the proteins that inhibit the host restriction system are synthesized A) before the entire T7 genome enters the cell. B) while the T7 genome is entering the cell but before it enters the nucleus. C) after the T7 genome is completely within the host cytoplasm. D) in response to the T7 genome binding to the host chromosome.
before the entire T7 genome enters the cell.
Rolling circle replication of the lambda genome differs from replication of a bacterial chromosome in that A) bidirectional replication forks are not formed. B) only a single strand of the genome is copied. C) no concatamers are formed. D) only a single strand of the genome is copied and no concatamers are formed.
bidirectional replication forks are not formed
Integration of Mu DNA into the host genome is essential for A) lytic growth. B) lysogenic growth. C) both lytic and lysogenic growth. D) neither lytic nor lysogenic growth.
both lytic and lysogenic growth.
What would a fucoxanthin carotenoid stain be most useful in identifying? A) brown or golden algae B) flagellated algae C) photosynthetic diatoms D) slime molds from other molds
brown or golden algae
What are the most abundant biomolecules in a typical fungal cell wall? A) amino acids B) carbohydrates C) lipids D) porins and channels
carbohydrates
Oomycetes (ʺwater moldsʺ) contain ________ in their cell walls, while most fungi have ________ in their cell walls. A) cellulose / chitin B) chitin / cellulose C) silica / chitin D) cellulose / silica
cellulose / chitin
Primary endosymbioses gave rise to ________ and secondary endosymbioses gave rise to ________. A) chloroplasts in algae / chloroplasts in plants B) mitochondria in eukaryotes / chloroplasts in eukaryotes C) chloroplasts and mitochondria in plants and red and green algae / chloroplasts in other eukaryotes D) chloroplasts and mitochondria in green and red algae / chloroplasts and mitochondria in diatoms
chloroplasts and mitochondria in plants and red and green algea / chloroplasts in other eukaryotes
Microsporidia were previously thought to be an early-branching taxon of Eukarya due to their parasitic lifestyle. However, new evidence suggests that they are more closely related to the A) ascomycetes. B) chytridiomycetes. C) glomeromycetes. D) zygomycetes.
chytridiomycetes
One of the earliest diverging lineages of fungi is the A) chytridiomycetes. B) zygomycetes. C) glomeromycetes. D) ascomycetes.
chytridiomycetes
Which microbial group is responsible for massive amphibian die-offs worldwide? A) cercozoans B) ciliates C) chytrids D) zygomycetes
chytrids
The life cycle of lambda phage is controlled by accumulation of repressor proteins. For lysogeny to occur A) cI protein predominates. B) Cro protein predominates. C) cII protein is repressed. D) cI protein is repressed.
cl protein predominates
In a freshwater pond, a green alga is likely to be A) only colonial. B) only filamentous. C) only unicellular. D) colonial, filamentous, multicellular, or unicellular.
colonial, filamentous, multicellular or unicellular
A concatemer is a A) combination of two or more repeated nucleotide sequences covalently linked together. B) complex of RNA-specific polymerases found only in bacteriophages. C) linker molecule that allows several phages to infect one host. D) polymeric protein
combination of two or more repeated nucleotide sequences covalently linked together.
Cellular receptors may be composed of A) proteins. B) carbohydrates. C) lipids. D) combinations of proteins, carbohydrates, and/or lipids.
combinations of proteins, carbohydrates, and/or lipids
Which spores are NOT involved in sexual reproduction of fungi? A) ascospores B) basidiospores C) conidia D) zygospores
conidia
The family of reoviruses contain dsRNA genomes use a ________ replication process. A) conservative B) semiconservative C) retroviral D) rolling circle
conservative
Identifying proteases being essential for the replication of a virus would suggest the virus A) lyses its host following genome replication. B) contains at least one polyprotein. C) has a single-stranded RNA genome. D) uses at least one set of overlapping genes.
contains at least one polyprotein.
Among the largest RNA genome viruses are ________ which contain a ________ genome. A) coronaviruses / dsRNA B) coronaviruses / positive ssRNA C) polioviruses / dsRNA D) polioviruses / positive ssRNA
coronaviruses / positive ssRNA
In designing a drug to inhibit poxvirus, the compound should localize in the hostʹs ________ to be most effective. A) nucleus B) endoplasmic reticulum C) cytoplasm D) Golgi complex
cytoplasm
You are attempting to mutate lambda to affect whether lysis or lysogeny occurs after infection. Which mutation would INCREASE the chances of LYSOGENY over lysis? A) deletion or inactivation of the cI gene B) deletion or inactivation of the cro gene C) overexpression of the cro gene D) deletion of both the cro and cI genes
deletion or inactivation of the cro gene
Staphylococcus aureus is known to cause all of the following diseases EXCEPT A) acne. B) arthritis. C) boils. D) dental caries.
dental caries
Bacteriophagesʹ genomes are typically composed of A) single-stranded RNA. B) single-stranded DNA. C) double-stranded RNA. D) double-stranded DNA.
double-stranded DNA
For a virus to cause a latent infection, it must possess A) ssDNA. B) ds DNA. C) dsRNA. D) Any type of viral genome can lead to a latent infection.
dsDNA
Prokaryotic restriction endonucleases are effective at destroying a virus whose genome consists of A) ds DNA. B) ssDNA. C) dsRNA. D) ssRNA.
dsDNA
Mu is a ________ virus with a ________ tail. A) ssRNA / filamentous B) dsRNA / helical C) ssDNA / filamentous D) dsDNA / helical
dsDNA / helical
Viruses that infect the hyperthermophilic Archaea tend to contain genomes that are composed of A) ssDNA. B) dsDNA. C) ssRNA. D) dsRNA.
dsDNA.
Reoviruses contain ________ genomes, and their replication occurs within the hostʹs ________. A) ssDNA / nucleus B) dsDNA / nucleus C) ssRNA / cytoplasm D) dsRNA / cytoplasm
dsRNA / cytoplasm
Obligate symbiotic fungi that form associations with plants by entering their cortical cells without invading the plant cellʹs membrane are called ________ and include the genus ________. A) ectomycorrhizae / Agaricus B) ectomycorrhizae / Glomus C) endomycorrhizae / Agaricus D) endomycorrhizae / Glomus
endomycorrhizae / Glomus
Which organisms would most likely be isolated from aerobic growth conditions with acetate and a soil sample heated to 80°C for 10 minutes? A) aerobic or facultative anaerobic acetogens B) endospore-forming bacteria C) hyperthermophilic heterotrophic bacteria D) mycoplasmas
endospore-forming bacteria
The amoebozoa that are parasitic for humans are the A) gymnamoebas. B) radiolarians. C) entamoebas. D) oomycetes.
entamoebas
Which group of amoebozoans is most likely to cause illness in humans? A) dictyostelium B) entamoebas C) gymnamoebas D) slime molds
entamoebas
A geologist going through a sediment core is likely to find remnants of ancient calcium carbonate containing ________ and silica containing ________. A) diatoms / chlorarachniophytes B) foraminiferans / diatoms C) chlorarachniophytes / foraminiferans D) foraminiferans / chlorarachniophytes
foraminiferans / diatoms
Mycoplasmas lack cell walls, thus A) they have a larger cytoplasmic volume. B) frequently exist as obligate symbionts. C) they have a higher sensitivity to osmotic lysis. D) they are unable to survive conditions under which protoplasts lyse.
frequently exist as obligate symbionts
The function of the parabasal body is to A) allow for photosynthesis to occur. B) give structural support to the Golgi complex. C) allow for the formation of energy from aerobic respiration. D) give structural support to the endoflagellum.
give structual support to the Golgi complex
Which characteristic is NOT associated with Vibrio spp.? A) aquatic B) gliding motility C) gram-negative D) pathogenic
gliding motility
The T4 phage protects its DNA from host restriction endonucleases by A) glucosylating cytosine bases in the T4 genome to prevent DNA cleavage. B) methylating all four bases (A, T, C, G) in the T4 genome to prevent DNA cleavage. C) integrating the viral genome into the host genome where it will not be degraded. D) circularizing the viral genome so that it will not be degraded.
glucosylating cytosine bases in the T4 genome to prevent DNA cleavage.
Which algae are most closely related to plants? A) red algae B) green algae C) brown algae D) euglenoids
green algae
The majority of basidiomycetes living in soil occur as A) diploid mycelia. B) diploid basidiocarps. C) haploid mycelia. D) haploid basidiocarps.
haploid mycelia
In contrast to bacterial endospores, fungal spores have substantially less resistance to A) chemicals. B) desiccation. C) heat. D) freezing.
heat
Which phenotypic assay could be used to determine whether a new Streptococcus spp. is of the pyogenes or viridans group? A) catalase assay with H2O2 B) hemolytic type after growth on a blood agar plate C) occurrence of cells being in clusters or as individual cells under a microscope D) product(s) formed during lactose fermentation
hemolytic type after growth on a blood agar plate
Regarding the viral membrane of an enveloped virus, the lipids are derived from the ________, and the proteins are encoded by ________. A) hostʹs cell membrane / viral genes B) virion / viral genes C) hostʹs cell membrane / hostʹs genes D) virion / hostʹs genes
host's cell membrane / viral genes
Which group of Eukarya has complicated the phylogenetics of the domain by first being thought of as ancient as compared to the more recent view of them being highly derived eukaryotes? A) dinoflagellates B) fungi C) hydrogenosome-containing eukaryotes D) stramenopiles
hydrogenosome-containing eukaryotes
A fungal mycelium is a large accumulation of ________, which may appear dusty or fuzzy due to the presence of ________. A) coenocytes / conidia B) coenocytes / mycorrhizae C) hyphae / conidia D) hyphae / mycorrhizae
hyphae / conidia
Which statement is TRUE regarding the ecological role of plant degradation by fungi? A) In brown rot the cellulose is attacked preferentially, and the lignin is left unmetabolized. B) In brown rot the lignin is attacked preferentially, and the cellulose is left unmetabolized. C) In white rot the cellulose is attacked preferentially, and the lignin is left unmetabolized. D) In white rot the lignin is attacked preferentially, and the cellulose is left unmetabolized.
in brown rot the cellulose is attacked preferentially, and the lignin is left unmetabolized
Viral replication is A) independent of the host cell's DNA but dependent on the host cell's enzymes and metabolism. B) independent of both the host cell's DNA and the host cell's enzymes and metabolism. C) dependent on the host cell's DNA and RNA. D) dependent on the host cell's DNA, RNA, enzymes, and metabolism.
independent of the host cell's DNA but dependent on the host cell's enzymes and metabolism
When a virus enters a host cell in which it can replicate, the process is called a(n) A) insertion. B) infection. C) prophage. D) excision.
infection
Which structural feature is common in BOTH Planctomycetes and Verrucomicrobia but RARELY found in bacteria outside these two phyla? A) intracellular compartmentalization B) prosthecae appendages C) sheathlike toga cell envelopes D) tubulins
intracellular compartmentalization
Viral replication occurs A) intracellularly. B) extracellularly. C) both intracellularly and extracellularly. D) either intracellularly or extracellularly, depending on the virus involved.
intracellularly
Many parabasalids lack ________, which makes them different than most other eukaryotes. A) endoplasmic reticula B) introns in their genomes C) mitochondria and hydrogenosomes D) Golgi complexes
introns in their genomes
Enveloped viral membranes are generally ________ with associated virus-specific ________. A) lipid bilayers / phospholipids B) protein bilayers / lipids C) lipid bilayers / proteins D) glycolipid bilayers / phospholipids
lipid bilayers/proteins
Some bacteriophage possess an enzyme similar to ________, which makes a small hole in the bacterial cell wall, allowing the viral nucleic acid to enter. A) peptidoglycanase B) infectase C) lysozyme D) nuclease
lysozyme
In a natural population of diverse slow-growing prokaryotic cells, what type of viruses would you expect to be most common? A) lytic bacteriophages B) enveloped viruses C) icosahedral viruses D) temperate bacteriophages
lytic bacteriophages
A virus that kills its host is said to be A) lytic or virulent. B) temperate. C) lysogenic. D) virulent or lysogenic, but not temperate.
lytic or virulent
As a consequence of infection by a temperate bacteriophage such as lambda, the host cell A) lyses as a result of bacteriophage release. B) never lyses but continues to divide and replicate both itself and the prophage. C) divides faster at moderate temperatures. D) may lyse or may continue to divide and replicate both itself and the prophage.
may lyse or may continue to divide and replicate both itself and the prophage
Which statement BEST describes the habitats of the fungi? A) Most fungi are aquatic, microscopic, and primarily freshwater. B) Most fungi are aquatic and primarily marine. C) Most fungi are terrestrial, microscopic, and inhabit soil or dead plant matter. D) Most fungi are terrestrial and macroscopic.
most fungi are terrestrial, microscopic, and inhabit soil or dead plant matter
Which of the following is NOT a unifying characteristic of diplomonads and parabasalids? A) having flagella B) lacking chloroplasts C) lacking mitochondria D) being multicellular
multicellular
In contrast to positive ssRNA viruses such as coronaviruses and polioviruses, the genome of retroviruses A) lacks genes encoding for tRNA primers. B) must first integrate into the hostʹs genome before transcription. C) is negative ssRNA. D) lacks ribonuclease activity.
must first integrate into the hostʹs genome before transcription.
Viral size is generally measured in A) micrometers. B) picometers. C) nanometers. D) centimeters.
nanometers
While not all members of ________ are pathogenic, two medically relevant species cause meningitis and gonorrhea in humans. A) Enterobacter B) Neisseria C) Shigella. D) Staphylococcus
neisseria
Which statement best describes our current understanding of the eukaryotic phylogenetic tree? A) Ribosomal RNA data allowed the development of the current phylogeny with 6 supergroups. B) Whole genome data was used to distinguish the 3 domains. C) The most recent analyses have conclusively shown the relationships of the 6 supergroups. D) New discoveries will probably lead to changes in the eukaryotic phylogenetic tree.
new discoveries will probably lead to changes in the eukaryotic phylogenetic tree
Chemolithotrophic ammonia-oxidization is a metabolic requirement for members of A) Nitrosomonas. B) Nitropseudomonas. C) Nitrosomonas and Nitrosospira. D) Nitrosomonas, Nitrosospira, and Nitropseudomonas.
nitrosomonas and nitrosospira
When packaged in the virion, the complete complex of nucleic acid and protein is known as the virus A) capsid. B) concatemer. C) nucleocapsid. D) envelope.
nucelocapsid
Giardia are diplomonads which have nuclei that A) appear as two separate chromosomes but are weakly joined. B) contain one small and one large nucleus per cell. C) have one nucleus enclosed in a mitosome and another nucleus in their cytoplasm. D) occur as two similar sizes per cell.
occur as two similar sizes per cell
The ability to form endospores in bacteria within Bacillales, Clostridiales, and Lactobacillales suggests the genotype/phenotype evolved A) at least three separate times in these divergent orders. B) at least once, and horizontal gene transfer among relatives explains its presence in other orders. C) only once in an ancestor to these three orders, due to the high number of genes required. D) either at least once and horizontal gene transfer among relatives occurred or once in a common ancestor.
only once in an ancestor to these three orders, due to the high number of genes required
Which genus would you most likely find in the photic layer of the oceans due to its abundance and aerobic chemoorganotrophic phenotype? A) Acetobacter B) Nitrosomonas C) Paracoccus D) Pelagibacter
pelagibacter
When a solution composed of bacteria and infectious virions are mixed and spread on annagar plate, ________ form where viruses lyse the host cells. A) insertion sequences B) plaques C) prophages D) colonies
plaques
Based on its function, which type(s) of viruses likely contain(s) a gene encoding for RNA replicase? A) dsDNA and ssDNA viruses B) positive ssRNA viruses C) positive and negative ssRNA viruses D) ssRNA and ssDNA viruses
positive and negative ssRNA viruses
Which type of viruses can be directly used for translation? A) dsRNA B) negative ssRNA C) positive ssRNA D) retroviruses
positive ssRNA
Polyproteins made from human viruses such as poliovirus must be ________ in order to yield the required functional units of the virus. A) able to interact with VPg proteins B) chemically modified with either glycolation or methylation C) post-translationally cleaved D) properly folded into secondary and tertiary structures
post-translationally cleaved
The order Lactobacillales within Firmicutes are also called the lactic acid bacteria, because these bacteria A) can aerobically catabolize lactic acid. B) can ferment lactate. C) produce lactate. D) uniquely require lactic acid as a precursor for cell wall biosynthesis.
produce lactate
Viral proteins are categorized as early, middle, and late. Early proteins typically are necessary for A) production of viral mRNA. B) packaging of DNA into the nucleocapsid. C) copying the viral genome. D) production of viral mRNA and copying the viral genome.
production of viral mRNA and copying the viral genome
Viruses infecting ________ are typically the easiest to grow in the laboratory. A) plants B) animals C) fungi D) prokaryotes
prokaryotes
Which phylum harbors the most functional diversity observed and also has the most cultured representatives? A) Actinobacteria B) Bacteroidetes C) Firmicutes D) Proteobacteria
proteobacteria
Which feature(s) differentiate(s) Actinobacteria from Firmicutes? A) absence/presence of a cell wall B) endospore production capability C) motility and chemotaxis abilities D) relative G+C content in their genomes
relative G+C content in their genomes
The phage Mu A) has a circular genome. B) repairs mutations in the host genome. C) replicates by transposition. D) has a circular genome, repairs host genome mutations, and can replicate by transposition.
replicates by transposition.
The genome of retroviruses contains genes to make all of the following EXCEPT A) structural proteins. B) repressor proteins. C) integrase. D) proteases.
repressor proteins
A drug designed to inhibit reverse transcriptase activity would target A) coronaviruses and rhabdoviruses. B) retroviruses. C) hepadnaviruses and retroviruses. D) viruses with RNA genomes.
retroviruses.
Which of the following enzymes would you expect to find in the virion of a retrovirus, but NOT in a bacteriophage? A) lysozyme B) methylase C) restriction enzymes D) reverse transcriptase
reverse transcriptase
The accessory pigment phycoerythrin is dominant in the ________ group of algae, which mostly lack flagella, have multicellular lifestyles, and occur in marine waters. Those in particular which deposit calcium carbonate in coral reef systems are classified as ________ algae. A) chlorophyte / coralline B) chlorophyte / rhodolithic C) rhodophyte / coralline D) rhodophyte / rhodolithic
rhodophyte / coralline
Evidence of ________ supports the hypothesis that eukaryotes are derived from bacteria. A) antibiotic resistance B) DNA content in the nucleus only C) ribosome characteristics only D) ribosome characteristics and DNA content in the nucleus
ribosome characteristics and DNA content in the nucleus
Of the taxa listed, which is NOT classified as a protist? A) Amoeba B) Euglena C) Giardia D) Saccharomyces
saccaromyces
What phenomenon accounts for the appearance of chloroplasts in some unicellularphototrophic eukaryotes? A) transformation of hydrogenosomes B) secondary endosymbioses of green or red algae C) primary endosymbioses of green or red algae D) horizontal gene transfer
secondary endosymbioses of green or red algae
The Baltimore Scheme to classify viruses contains a total of ________ groups based on ________. A) four / genome composition B) four / genome composition and transcription mechanism C) seven / genome composition D) seven / genome composition and transcription mechanism
seven / genome composition and transcription mechanism
The green alga Botryococcus braunii is a candidate for production of biofuel due to its ability to produce A) and withstand large amounts of alcohols. B) hydrogen gas. C) long-chain (C30-C36) hydrocarbons. D) short-chain (C8-C14) hydrocarbons.
short-chain (C30-C36) hydrocarbons
A gram-negative, obligately aerobic, bacillus-shaped bacterium that can degrade a large variety or aromatic compounds (making them potentially useful for bioremediation) is likely a(n) A) actinobacterium. B) enteric. C) pseudomonad. D) sphingomonad.
sphingomonad
Which of the following is NOT a member of the Eukarya? A) protists B) fungi C) spirochetes D) red algae
spirochetes
Herpes viruses can cause all of the following diseases in humans EXCEPT A) cancer. B) chicken pox. C) cold sores. D) spongiform encephalopathy.
spongiform encephalopathy.
Which feature, if changed, would NOT abolish M13ʹs utility as a cloning vector? A) ssDNA genome becoming a dsDNA genome B) loss of genes that make coat proteins C) replacing the segment of non-coding DNA in its genome with an indispensible gene D) switch from lysogenic to lytic lifestyle
ssDNA genome becoming a dsDNA genome
The majority of many important human viral diseases are caused by A) ssRNA viruses. B) ds RNA viruses. C) ss DNA viruses. D) ds DNA viruses.
ssRNA viruses
The ________ produce over 500 characterized antibiotics. A) Bacteroidetes B) mycobacteria C) pseudomonads D) streptomycetes
streptomycetes
All of the following can act as receptors for various bacteriophages EXCEPT A) iron transport proteins. B) flagella. C) Sugar transporters. D) cilia.
sugar transporters
Proteins made by a ribosome reading through the stop codon of a transcript without their own discrete ribosome binding sites A) are thought to be a primitive mechanism to avoid host defenses. B) appear most abundant in archaeal viruses and relatively uncommon in bacteriophages. C) suggest a relatively low level of protein product is essential for the virus due to the rare frequency of these events. D) create opportunities for viruses to make different capsid proteins.
suggest a relatively low level of protein product is essential for the virus due to the rare frequency of these events.
Based on oxygen requirements and metabolic strategies, you would most likely isolate an epsilonproteobacterium from A) anoxic and sulfate-rich waters. B) a plantʹs rhizosphere. C) sulfate-rich anoxic-oxic interfaces. D) sulfide-rich soils.
sulfate-rich anoxic-oxic interfaces
A pseudomonad that loses its R plasmid in the soil is LEAST likely to A) cause an infection in a human. B) colonize a surface. C) infect a shrub. D) survive a habitat dominated by antibiotic-producing Streptomyces spp.
survive a habitat dominated by antibiotic-producing Streptomyces spp.
As a consequence of the immune system in humans recognizing dsRNA as foreign A) dsRNA viruses rarely infect humans. B) dsRNA viruses quickly transcribe their genes into mRNA which is insensitive to immune responses. C) genomes of RNA viruses are often chemically modified to avoid recognition by human immune cells. D) the genomes of dsRNA viruses must avoid human immune cells during infection, including replicating their genomes within their own nucleocapsids.
the genomes of dsRNA viruses must avoid human immune cells during infection, including replicating their genomes within their own nucleocapsids.
Retroviruses are medically important viruses because A) they include the poliovirus. B) they include the influenza virus. C) they include all human pathogenic viruses. D) they include some viruses that cause cancer and HIV.
they include some viruses that cause cancer and HIV
What is the purpose of synthesizing a negative strand RNA in positive stranded ssRNA viruses? A) enable rolling circle amplification of the genome, which requires both strands of RNA B) enable transcription of genes occurring on both the negative and positive strands of the genome, such as overlapping genes C) proofreading of the genome to minimize mutations generated by the polymerase being passed onto virion progeny D) to serve as the complementary template sequence in genome amplification of the positive strand
to serve as the complementary template sequence in genome amplification of the positive strand
A thin, crescent-shaped organism with a single flagellum originating from a basal body and which folds back laterally across the cell would most likely be a member of the genus A) Trypanosoma. B) Glossina. C) Entamoeba. D) Gambiense.
trypanosoma
A drug that specifically inhibits the replication of the large DNA mass present in large mitochondria would be most effective at killing A) euglenids. B) ciliates. C) Trypanosoma spp. D) Toxoplasma spp.
trypanosoma spp.
The HIV genome consists of A) a single ds RNA molecule. B) two identical ssRNA molecules. C) two identical ssDNA molecules. D) a single DNA molecule.
two identical ssRNA molecules
Which of the following is NOT a trait of the Planctomycetes? A) undergo budding cell division B) have intracellular compartmentalization C) lack peptidoglycan D) undergo plant symbiosis
undergo plant symbiosis
The need for additional supplementation of ________ make developing growth media to culture mycoplasmas especially challenging. A) unsaturated fatty acids B) sterols C) vitamins D) unsaturated fatty acids, sterols, and vitamins
unsaturated fatty acids, sterols, and vitamins
Diatoms are A) found only in freshwater. B) more closely related to slime molds than to algae. C) usually morphologically symmetric. D) multicellular phototrophs.
usually morphologically symmetric
The ________ has been especially useful for genetic engineering because it is capable of triggering a substantial immune response without causing major adverse health effects. A) adenovirus B) polymyxavirus C) vaccina virus D) herpesvirus
vaccina virus
The growth of viruses in a culture is described as a one-step growth curve, because A) virion numbers show no increase during intracellular replication and can only be counted after the virions burst from the host cell. B) there is only one step in the viral life cycle which leads to only one replicative cycle in a culture. C) assembly and release actually occur in one step. D) the eclipse phase prevents the plating and enumeration of virions although new virions are produced at a steady rate during the eclipse phase.
virion numbers show no increase during intracellular replication and can only be counted after the virions burst from the host cell.
Isolating a bacterium of the ________ class would be of high impact due to it only having one cultured representative. A) Alphaproteobacteria B) Betaproteobacteria C) Epsilonproteobacteria D) Zetaproteobacteria
zetaproteobacteria
Treating wastewater requires the removal of organic material, and an ideal phenotype of a bacterium to do this would flocculate to make the cells settle (rather than staying in suspension) in a wastewater stream. Which species would be best for this application? A) Bartonella quintana B) Burkholderia cepacia C) Wolbachia pipientis D) Zoogloea ramigera
zoogloea ramigera
The unusual ability of ________ being flagellated and motile enables ________. A) ascospores / their dispersal in aquatic systems B) ascospores / spreading of those pathogens in blood C) zoospores / dispersal in aquatic systems D) zoospores / spreading of those pathogens in blood
zoospores / dispersal in aquatic systems
