Prokaryotes (Homework Test 6)
Endospores produced by the genera Bacillus and Clostridium are of clinical concern because ________. (Select all that apply) a. They have thick protein walls that make them resistant to disinfectants and antibiotics b. They are highly resistant to harsh environmental conditions. c. They are only destroyed by using alcohol-based gels d. They are responsible for infections with a high case fatality rate such as anthrax, gas gangrene, botulism and tetanus
a. They have thick protein walls that make them resistant to disinfectants and antibiotics d. They are responsible for infections with a high case fatality rate such as anthrax, gas gangrene, botulism and tetanus
Clinical classification of bacteria uses these features to develop a dichotomous key for rapid identification of a pathogenic bacterium: ________. (Select all that apply) a. cell shape and arrangement b. methane production c. gram staining and acid fast staining reactions d. oxygen utilization
a. cell shape and arrangement c. gram staining and acid fast staining reactions d. oxygen utilization
The domain Eukarya ________. a. diverged from Archaea b. diverged from Bacteria c. diverged from a now extinct domain of cells d. evolved from bacteria that developed a symbiotic relationship with other bacteria.
a. diverged from Archaea b. diverged from Bacteria
The slime layer functions to ________. a. prevent desiccation b. prevent osmotic lysis c. enhance attachment to surfaces d. prevent phagocytosis
a. prevent desiccation
A phylogenetic tree shows ________. (Select all that apply) a. proposed relatedness to a common ancestor b. evolutionary relationships between organisms c. a branching diagram d. groupings of organisms with similar physical features
a. proposed relatedness to a common ancestor b. evolutionary relationships between organisms c. a branching diagram
What innate bacterial system, built from which of the following monomers, protects these organisms from extreme changes in tonicity. a.Peptidoglycan b.Monosaccharides c.Hydrocarbons d.Amino acid
a.Peptidoglycan
Which bacterial organelle is one circular strand of DNA? a. Peptidoglycan b. Chromosome c.Inclusion body d. 70S Ribosome e. Nucleoid
b. Chromosome e. Nucleoid
In the first step of bacterial sporulation, the ________. a. chromosome is surrounded by a tough cortex and spore coat b. DNA is replicated c. plasma membrane encompasses the DNA d. endospore is released from the cell
b. DNA is replicated
In a clinical microbiology lab, what is the first step in identification of a pathogen from a patient sample? a. Negative stain to determine presence of capsule b. Gram stain for morphological analysis of cell wall plus size, shape and arrangement c. Flagellar stain to determine presence of flagella d. Simple Stain to determine cell size, shape and arrangement
b. Gram stain for morphological analysis of cell wall plus size, shape and arrangement
Chemicals produced by the human body will destroy bacterial cell walls. An example of this is ________. a. Lipopolysaccharide b. Lysozyme c. Penicillin d. Vancomycin
b. Lysozyme
One of the defining characteristics of prokaryotes is their lack of internal membranes. Which of the following are exceptions? a. Ribosomes b. Plasma membranes c. Thylakoids d. Carboxysomes e. Nucleosome
b. Plasma membranes c. Thylakoids d. Carboxysomes
According to the hypothesis of the evolution of life on earth as presented by Anderson et. al., the common ancestor cell must have had ________. (Select all that apply) a. Only DNA for genetic information b. Selectively permeable plasma membrane c. Basic metabolic pathways d. ATP for energy source
b. Selectively permeable plasma membrane c. Basic metabolic pathways d. ATP for energy source
What is the function of endospores for most bacterial species? a. Reproduction b. Survival
b. Survival
Which are the heritable traits that are evaluated by phylogenetic methods to determine evolutionary relatedness of prokaryotes and eukaryotic microbes in the three-domain model of classification? Choose the option that is experimentally more feasible if and when offered? AND what new taxonomic category is produced by this phylogeny? a. Kingdom b. The sequence of the 16S ribosomal RNA (rRNA) of the 70S ribosomes of prokaryotes c. The sequence of the 23S subunit of the 80S Rrna d. Class e. The sequence of the DNA coding for the 18S ribosomal RNA (rRNA) of the 80S ribosomes of eukaryotes f. Domain
b. The sequence of the 16S ribosomal RNA (rRNA) of the 70S ribosomes of prokaryotes e. The sequence of the DNA coding for the 18S ribosomal RNA (rRNA) of the 80S ribosomes of eukaryotes f. Domain
How do pili move bacterial cells? a. They produce a wave like undulating motion that moves the cell forward b. The tip of a pilus adheres to a surface and then shortens, causing the cell to be dragged forward c. As they twist, they propel the cell forward analogous the propeller on a boat d. They are driven by a rotor embedded in the cell wall
b. The tip of a pilus adheres to a surface and then shortens, causing the cell to be dragged forward
What is the correct definition of commensalism? a. Type of symbiosis in which neither organism benefits nor is harmed. b. Type of symbiosis in which one organism benefits but the other is unaffected. c. Type of symbiosis in which both organisms benefit. d. Type of symbiosis in which one organism benefits and the other is harmed.
b. Type of symbiosis in which one organism benefits but the other is unaffected.
Ureaplasmas and mycoplasmas ________.(Select all that apply) a. can only live in hypotonic environments b. have no cell wall c. are intracellular pathogens d. stain gram positive
b. have no cell wall c. are intracellular pathogens
The mycoplasmas are ________. a. gram negative b. wall-less c. acid fast d. gram positive
b. wall-less
Which of the following is a feature of prokaryotes cells? a. Absent or structurally simple cell walls b. Many complex membrane-bound organelles c. Genetic information carried by DNA in several linear chromosomes d. 70S ribosomes
c. Genetic information carried by DNA in several linear chromosomes
What is the name of the genus of the bacterium that has a Gram-negative envelope structure but cannot be stained by the Gram stain? a. Staphylococcus b. Serratia c. Mycobacteria d. Mycoplasma e. Borrelia
c. Mycobacteria
How do pili differ from fimbriae? a. Pili are more numerous with 100-400 per cell b. Only pili function in attachment to cells c. Only pili can be used for gene transfer and cell movement d. Only pili are found in both Gram-positive and Gram-negative bacteria
c. Only pili can be used for gene transfer and cell movement
What drives a bacterium to undergo conjugation AND where is the driving force found? a. Prophage b .Chromosome c. Plasmid d. Fertility factor
c. Plasmid d. Fertility factor
What is(are) the structural component(s) of the 70S ribosome? (Select all that apply) a. tRNA b. Peptidoglycan c. Ribosomal proteins d. rRNA
c. Ribosomal proteins d. rRNA
Glycogen granules in a bacterial cell ________. a. Provide phosphorus for synthesis of ATP b. Converts CO2 into glucose c. Store a carbohydrate source for synthesis of ATP d. Allow aquatic cyanobacteria to stay afloat
c. Store a carbohydrate source for synthesis of ATP
Bacterial species can be further divided into ________. (Select all that apply) a. Genera b. Domains c. Strains d. Serotypes
c. Strains d. Serotypes
New information about evolution has successfully challenged previous hypotheses. What has produced the new understandings? What is the new diagrammatic hypothesis that has come from the new information? What evolutionary concept does this work challenge? a. The tree of life now resembles a web. b. New understandings challenge the standard view of evolution of the three domains. c. The new understandings have revealed the extent of horizontal gene transfer. d. The tree of life now resembles a bush.
c. The new understandings have revealed the extent of horizontal gene transfer. d. The tree of life now resembles a bush.
The multiple hairlike extensions of the bacterial cell used for attachment are ________, and the long extension used for the transfer of genetic material is a ________. a. pili; fimbria b. flagella; pilus c. fimbriae; pilus d. pili; flagellum
c. fimbriae; pilus
A serotype ________. a. s a group of bacteria identified by having important genetic characteristics that make them different from a subspecies b. is a group of genetically similar individuals that are adapted for life in similar environments c .is a group of bacteria identified by response of specific antibodies to bacterial surface molecules d .is a group of bacteria of a particular species that demonstrate consistent, identifiable variations
c. is a group of bacteria identified by response of specific antibodies to bacterial surface molecules
Which bacterial organelle is responsible for protein synthesis? a. Nucleoid b. 80S ribosome c. Peptidoglycan d. 70S ribosome
d. 70S ribosome
Which Gram-positive, spore-forming, flagellated anaerobe produces a neurotoxin that inhibits acetylcholine resulting in respiratory paralysis. A great problem decades ago with canned food. Treated with antitoxin, penicillin, hyperbaric chamber, or respirator. Prevented by good food preservation techniques. a. Mycobacterium tuberculosis b. Clostridium perfringens c. Clostridium difficile d. Clostridium botulinum e. Mycoplasma pneumoniae f. Clostridium tetani g. Mycobacterium leprae h. Clostridioides difficile
d. Clostridium botulinum
In which situation would a bacterium most likely accumulate cytoplasmic inclusions? a. During mitotic cell division b. In times of nutrient deficiency c. During endospore formation d. In a habitat abundant in nutrients
d. In a habitat abundant in nutrients
If you observe rod-shaped, pink cells on a slide that had just been Gram stained, you can assume that the cell carries a. Exotoxin b. Endospore c. Sterols d. Lipid A e. Phospholipid
d. Lipid A
What part of a bacterial cell wall prevents osmotic lysis? a. Plasma membrane b. Teichoic acids c. Outer membrane d. Peptidoglycan
d. Peptidoglycan
How do bacteria help us as humans? (Select all that apply) a .Degrades environmental contaminants b. Normal microbiota protects us from infection c. Increases soil fertility d. Aids digestion of cellulose in ourselves and herbivores
a .Degrades environmental contaminants b. Normal microbiota protects us from infection c. Increases soil fertility d. Aids digestion of cellulose in ourselves and herbivores
What are the main structural features of the cell wall of Gram-positive bacteria? (Select all that apply) a. 6 to 12 layers of glycan sheets to produce a thick wall b. Embedded porin proteins c. Chains of teichoic acids d. Outer membrane of lipopolysaccharides
a. 6 to 12 layers of glycan sheets to produce a thick wall c. Chains of teichoic acids
What is not a major characteristic of a plasmid? a. All bacteria contain at least 1 or 2 plasmids b. Plasmids typically provide a selective advantage in unusual environments c. Chemicals d. Plasmids replicate independently of chromosomes e. Plasmids carry from 1-100s of genes not usually essential for life in a typical environment.
a. All bacteria contain at least 1 or 2 plasmids
What is the function of chains of teichoic acids in a Gram-positive bacterium? (Select all that apply) a. Attachment to host tissues in some pathogens like Streptococcus b. Regulation of cation flow c. Regulation of cell growth and division d. Provide protection from negatively charged phagocytic cells
a. Attachment to host tissues in some pathogens like Streptococcus b. Regulation of cation flow c. Regulation of cell growth and division d. Provide protection from negatively charged phagocytic cells
The survival of endospores requires that all components of the spore structure be very dehydrated. What molecule always associated with bacterial endospores ensures full dehydration? a. Calcium dipicolinate b. Fatty acids c. Phosphoric acid d. Thioglycolic acid e. Acetic acid
a. Calcium dipicolinate
A bacterial capsule ________. (Select all that apply) a. Can enable bacteria to attach firmly to a surface b. Is a glycocalyx that is gel-like and firmly attached to the cell c. Is a glycocalyx that is more fluid than a gel and is loosely attached to the cell d. Can enable bacteria to avoid phagocytosis
a. Can enable bacteria to attach firmly to a surface b. Is a glycocalyx that is gel-like and firmly attached to the cell d. Can enable bacteria to avoid phagocytosis
Endospores ________. (Select all that apply) a. Can survive after fossilization in amber for 25 million years b. Are easily killed by boiling c. Can survive after being frozen for 10,000 years d. Are chemical resistant
a. Can survive after fossilization in amber for 25 million years c. Can survive after being frozen for 10,000 years d. Are chemical resistant
What cellular structures contribute to the formation and maintenance of the shape of all bacterial cell morphologies? a. Cell wall b. Cytoskeleton c. Tubulin d. Sterols e. Hopanoids f. Cholesterol g. Steroids
a. Cell wall b. Cytoskeleton
What is the most important part of the bacterial endospore? a. Chromosome b. Cell wall c. Ribosomes d. Mitochondria
a. Chromosome
A unique feature of the Gram-negative bacterial cell wall is the presence of an outer membrane. Which statement is true concerning this feature? a. Contains the lipopolysaccharide, a pathogenic endotoxin b. Membrane consists of a bilayer of phospholipids c. The outer membrane contains teichoic acids linked to lipid A d. Membrane consists of a bilayer of lipopolysaccharides
a. Contains the lipopolysaccharide, a pathogenic endotoxin
How are species-specific arrangements of bacterial cells produced? a. Daughter cells dividing in different planes and remaining attached to each other b. Daughter cells dividing in the same plane but separating c. Daughter cells dividing in the same plane but only partially separating d. Daughter cells dividing in the same plane and remaining attached to each other
a. Daughter cells dividing in different planes and remaining attached to each other
Mycobacteria ________. a. Have acid-fast cell walls b. Have cell walls which contain mycolic acids linked to disaccharides c. Contains an outer hydrophobic layer high in lipids d. Are gram negative
a. Have acid-fast cell walls b. Have cell walls which contain mycolic acids linked to disaccharides c. Contains an outer hydrophobic layer high in lipids
Which of the following statements about the bacterial chromosome is incorrect? a. It is highly folded in the nucleus b. It has between 0.5-10 million base pairs. c. It contains about 800 genes are needed to produce essential cellular enzymes and structural components. d. Bacterial chromosomes have thousands of genes in their chromosomes e. Transcription only occurs on the outer surface of the coiled chromosome.
a. It is highly folded in the nucleus
What color would the following bacterial cell have in a Gram stain if it was described as having the following description from the cytoplasm to the environment: Cytoplasmic membrane, periplasmic space, cell wall, a mix of lipoteichoic acid and teichoic acid mixed with other polysaccharides as part of its glycocalyx. a. No color/no color b. Pink/red c. Green/turquoise d. Purple/blue
d. Purple/blue
What is the correct definition of mutualism? a. Type of symbiosis in which neither organism benefits nor is harmed. b. Type of symbiosis in which one organism benefits and the other is harmed. c. Type of symbiosis in which one organism benefits but the other is unaffected. d. Type of symbiosis in which both organisms benefit.
d. Type of symbiosis in which both organisms benefit.
Which anaerobic spore-forming bacterium causes gas-gangrene, fatal myonecrosis or acute food poisoning. a. Clostridium botulinum b. Mycoplasma pneumoniae c. Mycobacterium leprae d. Mycobacterium tuberculosis e. Clostridium perfringens f. Clostridium difficile g. Clostridioides difficile h. Clostridium tetani
e. Clostridium perfringens
What is the ultimate driver of osmosis and what moves across the membrane in this process? a. Salts b. Solvent c. Solutes d. Diffusion e. Entropy f. Concentration g. Water
e. Entropy g. Water
What molecule present in the mycobacteria prevents these bacteria from staining by Gram stain? a. Cholesterol b. Hopanoid c. Phospholipid d. Fatty acid e. Mycolic acid
e. Mycolic acid
With two membranes and a peptidoglycan layer, how does a Gram-negative cell move small, polar metabolites across the outer membrane? a. Simple diffusion through porins that allow passage through the outer membrane b. Facilitated diffusion through porin proteins c. Simple diffusion across the lipopolysaccharide layer d. Use of small microvesicles containing autolysin e. Size and charge limited diffusion through porins f. Active transport
e. Size and charge limited diffusion through porins
How do prokaryotes help to sustain life on Earth? (Select all that apply) a. Only prokaryotes can perform nitrogen fixation. b. CH4 generating bacteria live within roots of legumes and other plants. c. Photosynthetic prokaryotes produce glucose and oxygen gas used by all other aerobic organisms. d. Prokaryotes live in symbiotic relationships in stomachs of grazing animals to give them nutrients from plant material.
a. Only prokaryotes can perform nitrogen fixation. c. Photosynthetic prokaryotes produce glucose and oxygen gas used by all other aerobic organisms. d. Prokaryotes live in symbiotic relationships in stomachs of grazing animals to give them nutrients from plant material.
Peptidoglycan contains ________. (Select all that apply) a. Peptidoglycan monomers joined to form glycan chains b. Formation of 3-dimensional network via directly-linked tetrapeptide side chains or tetrapeptide side chains linked by pentaglycine crossbridges c. Disaccharides made from N-acetyl-galactosamine and N-propyl-muramic acid d. Disaccharides linked to peptide sidechains
a. Peptidoglycan monomers joined to form glycan chains b. Formation of 3-dimensional network via directly-linked tetrapeptide side chains or tetrapeptide side chains linked by pentaglycine crossbridges d. Disaccharides linked to peptide sidechains
What are all the sources that can contribute to a bacteria's genome? a. Plasmid b. Gene editing c. Gene rearrangement d. Chromosome e. Prophage f. Donor genes g. Mutation
a. Plasmid d. Chromosome e. Prophage f. Donor genes
Bacteria that demonstrate ________ have slight variations of shapes within the same species and may appear on a slide with these different shapes. a. Pleiomorphism b. Micromorphism c. Neomorphism d. Polymorphism
a. Pleiomorphism
What is the function of the cell wall? (Select all that apply) a. Prevents cell lysis in hypotonic environments b. Anchors flagella c. Prevents cell lysis in hypertonic environments d. Determines cell shape
a. Prevents cell lysis in hypotonic environments b. Anchors flagella d. Determines cell shape
The function of the outer membrane of gram negative bacteria is to (Select all that apply) a. Restrict the free diffusion of some antibiotics b. Allow small metabolites such as sugars, amino acids and nucleotides to diffuse through porin proteins c. Pinch off small microvesicles that contain autolysin d. Prevent osmotic lysis of the cell
a. Restrict the free diffusion of some antibiotics b. Allow small metabolites such as sugars, amino acids and nucleotides to diffuse through porin proteins c. Pinch off small microvesicles that contain autolysin
How do molecules pass through peptidoglycan to get into the cell? a. Simple diffusion through pores in peptidoglycan that formed as a result of incomplete crosslinking b. Facilitated diffusion through protein pores c. Endocytosis across the peptidoglycan barrier d. Active transport through protein pores
a. Simple diffusion through pores in peptidoglycan that formed as a result of incomplete crosslinking
Which of the following is a feature of prokaryotes cells? (Select all that apply) a. Structurally complex cell wall. b. Replication via binary fission c. True membrane-bound organelles d. 80S ribosome
a. Structurally complex cell wall. b. Replication via binary fission
Even small variations in which of the factors shown in the list below can contribute to pleomorphism in a bacterial population? a. Temperature b. Nutrients c. Genetics d. Pressure
a. Temperature b. Nutrients c. Genetics
How does the envelope of Gram-negative bacterial cells differ from that of Gram-positive bacterial cells? (Select all that apply) a. There is an outer membrane b. There are only 1 to 3 layers of glycan sheets c. Teichoic acids are present d. There is a direct cross-linkage between tetrapeptide side chains
a. There is an outer membrane b. There are only 1 to 3 layers of glycan sheets d. There is a direct cross-linkage between tetrapeptide side chains
What bacterium has biblical references, inspires fear, produces two forms a severe tuberculoid form wherein it infects nerves, skin and eyes and a less severe form. It can be treated with antibiotics and is prevented by vaccine commonly part of childhood immunizations in many parts of the world. What are its three names, and what in the vaccine that can prevent infection from this fearsome bacterium. a. Mycoplasma pneumoniae b. Mycobacterium tuberculosis c. Clostridium botulinum d. Clostridioides difficile e. Clostridium tetani f. Mycobacterium leprae
f. Mycobacterium leprae
What is the unusual arrangement of Corynebacterium diphtheria that we sometimes see on a microscope slide? a. Sarcinae b. Strepto- c. Diplo- d. Filamentous e. Tetrads f. Staphylo g. Palisade h. Hyphal
g. Palisade
What bacterium from the list shown below, has all of the following attributes: Found in soil and in low numbers as part of the healthy human intestinal microbiome; are spore-formers; are held in check as part of the healthy human intestinal microbiome; antibiotic and/or laxative overuse allow overgrowth and toxin production resulting in pseudomembranous colitis manifested as frequent diarrhea; pan-antibiotic resistant strains are debilitating and can be life threatening; best treatment at this stage is fecal bacteriotherapy commonly called fecal transplant and has proven to be very successful. a. Clostridium tetani b. Mycobacteria tuberculosis c. Clostridium difficile d. Clostridium perfringens e. Mycoplasma pneumoniae f. Mycobacteria leprae g. Clostridium botulinum h.Clostridioides difficile
h.Clostridioides difficile
