BIO EXAM #1
Bacterial endospores are protected from chemicals and various lytic enzymes due to the presence of the spore layer called the _________.
Coat
Which of the following is not considered a macronutrient? Carbon (C) Calcium (Ca) Potassium (K) Cobalt (Co)
Cobalt (Co)
The region of the cell bounded by the plasma membrane is the _________.
Cytoplasm
Bacterial and archaeal ribosomes are known as _________ribosomes, based on their sedimentation coefficient. 50S 30S 80S 70S
70S
Which of the following describes an organism that can have plasma membranes composed a monolayer of lipids? Bacteria Eukarya Archaea
Archaea
Which of the following describes an organism that has plasma membranes composed of glycerol diethers and diglycerol tetraethers? Bacteria Archaea Eukarya
Archaea
Which of the following describes an organism that lacks linear chromosomes and peptidoglycan cell walls? Archaea Bacteria Eukarya
Archaea
Which of the following describes an organism that lacks linear chromosomes but has peptidoglycan cell walls? Archaea Bacteria Eukarya
Bacteria
________________ was the first to isolate a root nodule bacterium capable of nitrogen fixation.
Beijerinck
Which of the following describes an organism that contains 80S ribosomes? Bacteria Eukarya Archaea
Eukarya
Which of the following describes an organism that has DNA wrapped around histones? Bacteria Eukarya Archaea
Eukarya
Which of the following describes an organism that rarely contains plasmids? Eukarya Bacteria Archaea
Eukarya
Which of the following has flagella that wave back and forth? Archaea Bacteria Eukarya
Eukarya
T/F Archaeal and bacterial pili are identical in structure and function.
F
T/F Archaeal flagella (archaella) are superficially similar to bacterial flagella, although archaella are much thicker than bacterial flagella.
F
T/F Archaeons power their flagella by proton motive force (PMF), whereas bacteria empower their flagella by ATP hydrolysis.
F
T/F Cell walls of most archaea and bacteria contain peptidoglycan.
F
T/F Coated pits containing clathrin do not permit concentration of ingested macromolecules prior to endocytosis.
F
T/F Endospores are reproductive structures.
F
T/F Extant microorganisms are organisms from the fossil record that are no longer present on Earth today.
F
T/F Germination is one process by which bacterial cells can reproduce.
F
T/F Gram-positive bacteria have a structurally and chemically more complex cell wall than Gram-negative bacteria.
F
T/F Gram-positive bacteria have a thinner layer of peptidoglycan than Gram-negative bacteria.
F
T/F In an endospore, the protein coat forms a layer external to the exosporium.
F
T/F In terms of membrane lipids, the plasma membranes of archaeons are more similar to those of the eukaryotes than to membranes of bacteria.
F
T/F Membrane vesicles are used to transport material between cells as an alternative to protein secretion systems. Regardless of the nature of the bacterial envelope, all vesicles are produced by the same mechanism.
F
T/F Microbiologists study a variety of organisms, but all are considered either Bacteria or Archaea.
F
T/F Most substances are able to undergo passive diffusion across the plasma membrane in order to enter a cell.
F
T/F Phosphorus can be obtained from organic sources only.
F
T/F Sulfur can be obtained from inorganic sources only.
F
T/F The cell membrane is a rigid structure that provides bacteria with their characteristic shapes.
F
T/F The distribution of lipids in the plasma membrane of eukaryotes is symmetrical.
F
T/F The hydrocarbons found in the membranes of archaea are identical to those found in bacteria.
F
T/F The original differentiation of prokaryotes and eukaryotes was based on structures found in prokaryotes that are lacking in eukaryotes.
F
T/F The rotation of bacterial flagella is powered by ATP hydrolysis.
F
T/F The type strain is the most representative strain of a particular species.
F
T/F Unlike members of domain Bacteria, most archaeans have linear chromosomes.
F
T/F Viruses are not generally studied by microbiologists because they are not classified as living organisms.
F
T/F Viruses constitute the fourth domain of life in current biological classification schemes.
F
Which of the following bacterial structures are most directly linked to swimming motility in chemotaxis? Capsule Pili Fimbriae Flagella
Flagella
The inner membrane system of chloroplasts consists of flattened sacs called _________that form stacks called _________.
thylakoids, grana
A(n) ______________ simply represents phylogenetic relationships but does not indicate which organisms are more primitive relative to others. In contrast, a(n) _____________ gives a node that serves as the common ancestor and shows the development of the species from this origin.
unrooted tree ; rooted tree
Some molecules needed for survival cannot be synthesized by the cell but instead must be obtained from the environment. These types of molecules include vitamins and amino acids and are collectively called ______ ______.
Growth factors
_________are required organic compounds because they are essential cell components or precursors of such components that cannot be synthesized by the organism.
Growth factors
Nutrient uptake and diffusion of molecules into the bacterial cell become more efficient as the surface area-to-volume ratio _________.
Increases
____________ microbiology involves the use of microorganisms to make products such as antibiotics, vaccines, steroids, alcohols, vitamins, amino acids, and enzymes.
Industrial
Three of the SSU rRNA sequences of three organisms have been compared. For organisms 1 and 2, two of the twelve nucleotides in the sequence are different. For organisms 1 and 3, six of the twelve nucleotides are different. Which organism has a greater evolutionary distance from organism 1? a) Organism 2 b) Organism 3 c) The evolutionary distance is the same. d) Evolutionary distance cannot be predicted from this data.
Organism 3
_________is a peptidoglycan-like molecule found in the cell walls of some archaea.
Pseudomurein
_________are the site of protein synthesis in the cell.
Ribosomes
A(n) _________is a layer of protein or glycoprotein that exhibits a pattern resembling floor tiles.
S-layer
_________bind ferric iron and transport it into a bacterial cell.
Siderophores
T/F A eukaryotic flagellum can either push a cell through a liquid environment or pull it through depending on the undulating pattern of movement.
T
T/F A phagosome containing the engulfed bacteria combines with a lysosome containing enzymes to produce a phagolysosome.
T
T/F Chloroplasts are the site for both the light and dark reactions of photosynthesis.
T
T/F Complete bacterial ribosomes are comprised of approximately 55 proteins and three molecules of ribosomal RNA.
T
T/F Endotoxic shock, resulting from the release of endotoxin by bacteria infecting a patient, is only caused by Gram-negative bacteria.
T
T/F John Tyndall demonstrated that microorganisms present in the air are carried on dust particles.
T
T/F Low-density lipoprotein is brought into the cell by receptor-mediated endocytosis.
T
T/F Lysosomes function in the destruction and recycling of old organelles.
T
T/F M. J. Berkeley demonstrated that the great potato blight of Ireland was caused by a water mold (then thought to be a fungus).
T
T/F Many archaeal genomes include chromosomes and plasmids.
T
T/F Methanogens may contribute to the greenhouse effect and global warming due to methane production.
T
T/F Microvesicles and exosomes are both membrane-bound extracellular vesicles. They differ in that microvesicles are surrounded by a portion of the outer cell membrane following exocytosis, whereas exosomes form when an endomembrane pinches off inwardly.
T
T/F Pinocytosis is defined as the movement of liquid materials into the cell
T
T/F Some archaeal cells lack a cell wall.
T
T/F Some archaeons are symbionts in animal digestive tracts.
T
T/F Some microorganisms are useful in bioremediation processes that reduce the effects of pollution.
T
T/F Spore formation is initiated when there is a scarcity of nutrients.
T
T/F Sterol-like molecules called hopanoids are thought to be important for the structural integrity of many bacteria because of their suspected role in membrane stabilization.
T
T/F The DNA of some archaeons is stabilized by association with archaeal histone proteins forming particles resembling eukaryotic nucleosomes.
T
T/F The endoplasmic reticulum is mostly devoid of ribosomes (smooth ER) when cells are producing large quantities of lipid.
T
T/F The endosymbiotic hypothesis is generally accepted as the origin of eukaryotic organelles.
T
T/F The enzymes found in lysosomes were synthesized by ribosomes located on the endoplasmic reticulum.
T
T/F The extreme insolubility of ferric iron leaves little free iron available for transport into bacterial cells.
T
T/F The first disease to be identified as being caused by a virus was tobacco mosaic disease.
T
T/F The majority of mitochondrial proteins are manufactured under the direction of the nuclear DNA by cytoplasmic ribosomes.
T
T/F The membrane-bound structure that contains the chromosomes of eukaryotes is called the nucleus.
T
T/F The relationship between specific bacteria and specific diseases was first demonstrated by Koch.
T
Which of the following is useful in distinguishing between bacterial, archaeal, and eukaryotic cells? a) The use of DNA for the storage of genetic information b) The presence of ribosomes for the synthesis of proteins c) The presence of membrane-delimited organelles within the cytoplasm d) All of the choices are correct.
The presence of membrane-delimited organelles within the cytoplasm
A microbe is discovered living in an extreme environment near a deep sea vent. The microorganism lacks a nucleus and peptidoglycan in its cell wall, but it does have unusual membrane lipids. This species is most likely a member of the Domain _________ a) Archaea b) Bacteria c) Eukarya d) Animalia
a) Archaea
Which of the following parts of the Golgi complex receives materials from the ER? a) Cis face b) Trans face c) Cisternal edges d) None of the choices are correct.
a) Cis face
Lysosomes are membrane-bound vesicles that arise from the _________. a) Golgi apparatus b) cell membrane c) nucleus d) endoplasmic reticulum e) mitochondria
a) Golgi apparatus
Select a harmful effect that can result from bacterial colonization of the human body. a) Invasion of host cells b) Production of vitamins c) Digestion of food d) Immune system development
a) Invasion of host cells
Which of the following experiments is used to identify new pathogens? a) Koch postulates b) Endosymbiotic theory c) Stanley Miller experiment d) Pasteur's swan-neck experiment
a) Koch postulates
The first evidence of primitive cellular life was the 1977 discovery of microbial fossils in the Swartkoppie chert, a type of granular sedimentary rock rich in silica. Why is this evidence not considered definitive? a) Objects that look like cells can be formed by geological forces as the rocks formed. b) There is no evidence of carbon dioxide, which is needed to prove that living organisms respired. c) There was no evidence of water, therefore it is questionable whether cells could have been present. d) The fossils did not look like bacterial cells.
a) Objects that look like cells can be formed by geological forces as the rocks formed.
Which of the following is most likely synthesized on free ribosomes? a) Polypeptide chains that form enzymes that function in glycolysis b) Electron carriers of the electron transport chain c) Polypeptide chains that form immunoglobulin molecules d) Lysosomal enzymes
a) Polypeptide chains that form enzymes that function in glycolysis
Choose the correct scientific name for a microbial species. a) Staphylococcus aureus b) Escherichia Coli c) Streptococcus Pyogenes d) klebsiella Pneumoniae
a) Staphylococcus aureus
Which of the following best describes eukaryotic cell cytoplasm? a) The compartment within the cell membrane that contains various organelles and metabolic enzymes b) The liquid fraction of the cell c) The compartment within the mitochondria, nucleus, endoplasmic reticulum, and Golgi (location for metabolism) d) The compartment between the cell membrane and the cell wall and is the location of the electron transport system
a) The compartment within the cell membrane that contains various organelles and metabolic enzymes
Which of the following statements is FALSE when comparing bacterial and eukaryotic cytoskeletal proteins? a) The cytoskeletal proteins found in bacterial cells are structurally and functionally unrelated to those found in eukaryotic cells. b) There are homologues of both microtubules and actin filaments found in bacterial cells. c) Similarities between the bacterial and eukaryotic cytoskeleton suggest these proteins evolved early in the formation of life on earth. d) Like the eukaryotic cytoskeleton, bacterial cytoskeletal proteins function in cell division, protein positioning, and determination of cell shape.
a) The cytoskeletal proteins found in bacterial cells are structurally and functionally unrelated to those found in eukaryotic cells.
Which best describes the motility of eukaryotic organisms using flagella? a) The flagella whip back and forth, pushing the cell along b) The flagella spin like a propeller, pushing the cell along c) The flagella spin like a propeller, pulling the cell along d) The flagella grabs onto surfaces and pulls the cell along
a) The flagella whip back and forth, pushing the cell along
What term is used to describe the individual flattened, membrane delimited sacs that compose the grana in a chloroplast? a) Thylakoid b) Chlorophyll c) Stroma d) Matrix
a) Thylakoid
Which of the following does not contribute to packaging the relatively large bacterial chromosome into the nucleoid region of the cell? a) Thymine-rich domains b) Supercoiling c) Nucleoid-associated proteins d) Macromolecular crowding
a) Thymine-rich domains
How many layers of membrane does the nuclear envelope have? a) Two b) One c) Varies on the organism d) Three
a) Two
Lipids with polar and nonpolar ends are said to be _________. a) amphipathic b) amphibolic c) bilateral d) None of the choices are correct.
a) amphipathic
Diglycerol tetraether lipids _________. a) are a characteristic feature of thermophilic Archaea b) tend to make the membrane less rigid c) are found in some bacteria and some Archaea d) form typical bilayer membranes in thermophilic Archaea of the genus Thermoplasma
a) are a characteristic feature of thermophilic Archaea
Archaea with a plasma membrane composed of a tetraether monolayer would most likely be found _________. a) at a temperature of 90oC b) in an anaerobic environment c) in the soil d) in the mammalian gut e) at a pH of 2
a) at a temperature of 90oC
An external structure unique to archaea are the _________. a) cannulae b) pili c) flagella d) fimbriae
a) cannulae
The spore layer containing peptidoglycan is the _________. a) cortex b) germ cell wall c) sporangium d) inner membrane e) protein coat
a) cortex
In phagocytosis, the digested contents are eliminated by _________. a) exocytosis b) opsonization c) endocytosis d) C3b
a) exocytosis
External structures that are found in archaea but not bacteria are _________. a) hami b) flagella c) pili d) peptidoglycan
a) hami
Studies by Emil von Behring and Shibasaburo Kitasato demonstrated that inactivated toxins can induce the synthesis of antitoxins in the blood of rabbits. These antitoxins (antibodies) are the basis of _________ a) humoral immunity b) cell-mediated immunity c) antibiotic immunity d) phagocyte-mediated immunity
a) humoral immunity
The enzymes and electron carriers involved in electron transport and oxidative phosphorylation are located in the _________ membrane of the mitochondrion. a) inner b) outer c) inner and outer d) neither inner nor outer
a) inner
A filamentous organelle comprised of tubulins with a diameter of 25 nm is called _________. a) microtubule b) microfilament c) intermediate filament d) mycelia
a) microtubule
Chemotaxis is a process by which bacteria _________. a) move toward an attractant or away from a repellent b) avoid phagocytosis c) respond metabolically to the presence of autoinducer molecules d) move on solid surfaces by means of type IV fimbriae
a) move toward an attractant or away from a repellent
Proteins that are loosely associated with the cytoplasmic membrane are called _________proteins. a) peripheral b) integral c) external d) internal
a) peripheral
Flimmer filaments ________. a) permit flagella to pull rather than push the cell b) are components of all eukaryotic flagella c) function to move cells on solid surfaces d) are found on whiplash flagella
a) permit flagella to pull rather than push the cell
A new microbe was isolated from a water sample. The species was found to be motile and contained a nucleus and other membrane-bound organelles. After analysis, it was found to obtain necessary nutrients by ingesting other microbes. This species is a(n) _________ a) protozoan b) bacterium c) fungus d) algae
a) protozoan
The formation of carbohydrate (CO2 fixation) in the dark reaction of photosynthesis, takes place in the _________. a) stroma b) cytoplasm c) thylakoid membrane d) nucleus
a) stroma
When observing flagella distribution patterns, bacteria with a single flagellum at each pole are called _________ bacteria.
amphitrichous
In many spirochetes, multiple flagella combine to form a bundle known as a(n) _________fibril, which winds around the cell and confers motility on the cell.
axial
An archaeon in a nutrient-poor environment is most likely to use _________or nutrient uptake. a) passive diffusion b) ABC transport c) group translocation d) facilitated diffusion
b) ABC transport
If you found a microbe with an S-layer as the major component of its cell wall, how would you identify this microbe? a) As a Gram-negative bacterium b) As an archaeon c) As a Gram-positive bacterium d) As a eukaryote
b) As an archaeon
_________are hollow tube-like structures that hold some archaeal daughter cells together after cell division while _________ are grappling hook-like structures that appear to attach archaeal cells to surfaces. a) Pili; hami b) Cannulae; hami c) Hami; fimbriae d) Cannulae; pili
b) Cannulae; hami
Which of the following advances best describes the idea that today we may be experiencing a second golden age of microbiology? a) Koch postulates b) Genomic testing c) Light microscopy d) Biochemical testing
b) Genomic testing
What is the name of the protein that eukaryotic DNA is wrapped around to form nucleosomes? a) Chromatin b) Histones c) Sterols d) Ribosomes
b) Histones
Antiseptic surgery was pioneered by _________. a) Pasteur b) Lister c) Jenner d) Kitasato
b) Lister
Penicillin inhibits bacterial growth by preventing cross-linking during peptidoglycan synthesis. Why does penicillin not inhibit the growth of archaeal cells? a) Archaeal cells do not have a cell wall. b) Most archaeal cells have a cell wall, but it is not composed of peptidoglycan. c) Penicillin is unable to penetrate the lipid outer membrane that blocks access of penicillin to the peptidogycan crosslinking enzymes. d) Pencillin is unable to penetrate the S layer to reach the peptidoglycan layer underneath.
b) Most archaeal cells have a cell wall, but it is not composed of peptidoglycan.
Who is credited with developing a vaccine against chicken cholera? a) Koch b) Pasteur c) Jenner d) Lister
b) Pasteur
Which of the following protects bacteria from lysis in dilute solutions and helps to determine their cellular morphology or shape? a) Plasma membrane b) Peptidoglycan c) Capsule d) Gas vacuoles
b) Peptidoglycan
Which of the processes named here is the least likely to contribute to the evolution of genetic diversity of bacteria and archaea? a) Mutation b) Sexual reproduction c) Binary fission d) Horizontal gene transfer
b) Sexual reproduction
The concept of a prokaryote was first fully outlined in 1962 by _________ a) Gilbert and Cech b) Stanier and Van Niel c) Watson and Crick d) Hershey and Chase
b) Stanier and Van Niel
A pathogenic bacterial species has mutated and is no longer able to synthesize a capsule. Which outcome would you predict? a) The mutated bacteria will be more virulent. b) The mutated bacteria will not be able to cause disease as readily. c) The mutated bacteria will be protected from plasmolysis in hypertonic environments. d) The mutated bacteria will undergo osmotic lysis in hypotonic environments.
b) The mutated bacteria will not be able to cause disease as readily.
The "cis" side of the Golgi complex refers to which of the following? a) The inside of the Golgi complex b) The side of the Golgi facing the endoplasmic reticulum c) The side of the Golgi that fuses with lysosomes d) The side of the Golgi facing the cell membrane
b) The side of the Golgi facing the endoplasmic reticulum
One type of archaeon, Haloquadratum walsbyi, is shaped like a postage stamp with dimensions of 2 µm x 3 µm x 0.25 µm. What advantage would this shape provide? a) This shape enables these bacteria to float on surfaces and obtain better light exposure. b) This shape increases the surface-to-volume ratio enabling more efficient nutrient uptake. c) This shape is difficult for phagocytic cells to attach to and engulf. d) This shape is more conducive to the formation of biofilm communities.
b) This shape increases the surface-to-volume ratio enabling more efficient nutrient uptake.
The ribosomal RNA studies that led to the division of prokaryotic organisms into the Bacteria and the Archaea were begun by _________ a) Pasteur b) Woese c) Needham d) Watson
b) Woese
Archaeal pili differ from bacterial pili due to the presence of _________. a) a basal body b) a central lumen c) pilin proteins d) grappling hooks
b) a central lumen
A newly discovered microorganism has a circular chromosome that is complexed with histones but not enclosed within a membrane. The plasma membrane lipids include glycerol dietethers and diglycerol tetraethers. There are no mitochondria or chloroplasts, but the cells do contain 70s ribosomes. This microbe most likely is _________. a) a bacterium b) an archaeon c) a protozoan d) a fungus
b) an archaeon
A lysosome _________. a) contains enzymes specific to the receptors on the bacterium being eliminated b) contains lysozyme and proteases that digest bacteria c) is an organelle that makes a bacterium motile d) is found only inside the bacterium being ingested
b) contains lysozyme and proteases that digest bacteria
The movement of dissolved solutes from a region of higher concentration to a region of lower concentration is called _________. a) osmosis b) diffusion c) isotonic d) hypotonic
b) diffusion
A new microbe has been discovered in the rumen of sheep. Microscopy shows no evidence of a nuclear membrane, and biochemical studies of the cell wall demonstrate the lack of peptidoglycan. Metabolic studies show that this microbe generates methane. This microbe would most likely be classified in _________ a) domain Bacteria b) domain Archaea c) domain Eukarya, Kingdom Fungi d) domain Eukarya, Protists
b) domain Archaea
Scientists study microorganisms on Earth today to search for life forms elsewhere, as well as to explore the origins of life on Earth. These microorganisms that are studied are referred to as _________ a) existing b) extant c) extinct d) extirpated
b) extant
The concept that human and animal diseases are caused by microorganisms is called the _________ a) cell theory b) germ theory c) causative theory d) disease theory
b) germ theory
Proteins that are embedded within the cytoplasmic membrane and not easily extracted are called _________proteins. a) peripheral b) integral c) external d) internal
b) integral
Archaeal cell walls _________. a) are similar to those of Gram-negative bacteria b) lack murein and D-amino acids c) are unlike bacterial cells; they all have the same composition d) are disrupted by treatment with lysozyme or penicillin
b) lack murein and D-amino acids
Protein filaments with a diameter of 4-7 nm that play a role in cell movement and shape change are called _________. a) microtubules b) microfilaments c) intermediate filaments d) mycelia
b) microfilaments
The process by which a cell imports large particles by enclosing them in vesicles pinched off from the plasma membrane is called _________. a) exocytosis b) phagocytosis c) pinocytosis d) nutrient cytosis
b) phagocytosis
Shrinkage of the plasma membrane away from the cell wall when the bacterium is placed in a hypertonic environment is called _________ a) osmolysis b) plasmolysis c) hydrolysis d) hypertonolysis
b) plasmolysis
Bacterial cells that are variable in shape are called _________. a) vibrio b) pleomorphic c) coccobacilli d) hyphal
b) pleomorphic
Endocytic events _________. a) add membrane to the cell surface b) remove the membrane from the cell surface c) have no effect on the plasma membrane d) change the membrane composition
b) remove the membrane from the cell surface
The nucleolar organizer is a part of a specific chromosome that directs the synthesis of _________. a) transfer RNA (tRNA) b) ribosomal RNA (rRNA) c) messenger RNA (mRNA) d) heterogeneous nuclear RNA (hnRNA)
b) ribosomal RNA (rRNA)
A cell morphology unique to archaea is _________. a) coccus b) square c) curved rods d) spiral e) rods in chains
b) square
The evolution of membrane-bound organelles and thus compartmentalization within eukaryotic cells likely arose due to all of the following except _________. a) the need to increase surface area to maximize those processes that take place in a membrane, such as oxidative phosphorylation b) the need to prevent mixing of cellular macromolecules such as proteins and polysaccharides c) the need to spatially separate simultaneous processes in order to ensure independent control d) the need to increase the overall amount of cell membrane to maximize efficiency of transport systems
b) the need to prevent mixing of cellular macromolecules such as proteins and polysaccharides
The term used to describe bacteria that are rod-shaped is _________. coccus bacillus vibrio coccobacillus
bacillus
Bacterial flagella are composed of three parts: the _________body, which is embedded in the cell, the hook, and the _________, which is the longest part of the flagellum.
basal, filament
Bacterial strains that are characterized by biochemical differences are called __________.
biovars
The primary lipid components of the membranes of extreme thermophiles are _________. a) sulfolipids b) cholesterol c) 40 carbon diglycerol tetraethers d) 20 carbon diglycerol diethers
c) 40 carbon diglycerol tetraethers
What is a common location for both bacterial ribosomes and eukaryotic ribosomes? a) Nucleus b) Endoplasmic reticulum c) Cytoplasm d) Cytoplasm and rough endoplasmic reticulum
c) Cytoplasm
Which cell type ranges in size from about 10-100 µm, has 80s ribosomes, and has internal compartments bounded by membranes? a) Archaea b) Bacteria c) Eukarya
c) Eukarya
Which of the following statements is false regarding the differences between bacterial and eukaryotic cytoskeletal proteins? a) The bacterial protein FtsZ is a homologue of the eukaryotic protein tubulin, and MreB and Mbl are homologues of actin. b) Cytoskeletal proteins in both eukaryotes and bacteria function in cell division, protein localization, and determination of cell shape. c) Eukaryotic cells have cytoskeletal fibers comprised of tubulin and actin proteins, whereas bacterial cells lack cytoskeletal proteins. d) Proteins in the cytoplasm of bacterial cells are structurally similar to the tubulin and actin found in eukaryotic cells.
c) Eukaryotic cells have cytoskeletal fibers comprised of tubulin and actin proteins, whereas bacterial cells lack cytoskeletal proteins.
Choose the incorrect statement about Koch's postulates. a) Isolation of the microorganism in pure culture in the lab b) Infecting a suitable animal model and causing symptoms of the same disease c) Infecting an animal model without causing symptoms of the same disease d) Isolating the microorganism from all cases of the disease
c) Infecting an animal model without causing symptoms of the same disease
Who is credited with developing and documenting the first vaccination procedure against smallpox? a) Koch b) Pasteur c) Jenner d) Lister
c) Jenner
Which of the following is a component of the outer membrane in Gram-negative bacteria that results in septic shock upon entering the bloodstream? a) Porin proteins b) Teichoic acids c) Lipopolysaccharide d) Peptidoglycan
c) Lipopolysaccharide
Examine the following genetic sequences and determine which pair are the most similar based on their ED (evolutionary distances). Species 1 = ATTGGCCATT Species 2 = ATTCCGGTTT Species 3 = TTTGGCCATT Species 4 = ATTCCCCCCC a) Most similar are Species 2 = ATTCCGGTTT Species 3 = TTTGGCCATT b) Most similar are Species 1 = ATTGGCCATT Species 4 = ATTCCCCCCC c) Most similar are: Species 1 = ATTGGCCATT Species 3 = TTTGGCCATT
c) Most similar are: Species 1 = ATTGGCCATT Species 3 = TTTGGCCATT
When analyzing the outer membrane of Gram-negative bacteria, which part of lipopolysaccharide induces an antibody response? a) Lipid A b) Core polysaccharides c) O antigen d) Teichoic acids
c) O antigen
Which of the following cells will be expected to contain the most active lysosomes? a) Intestinal cell b) Skin cell c) Phagocytosing white blood cell d) Kidney cell e) Brain cell
c) Phagocytosing white blood cell
Which of the following structures are external to both bacterial and archaeal cells? a) Ribosomes b) Hami c) Pili d) Peptidoglycan
c) Pili
In which of the following organelles would you expect to find protein synthesis occurring? a) Smooth endoplasmic reticulum b) Nucleus c) Rough endoplasmic reticulum d) Golgi
c) Rough endoplasmic reticulum
A lysosome containing undigested material is called _________. a) a phagosome b) an endosome c) a residual body d) a coated vesicle
c) a residual body
Archaea often live in nutrient-poor environments. In order to ensure survival, they must _________. a) acquire nutrients inside the cell at lower concentrations than the external environment, which requires passive transport mechanisms b) develop metabolic pathways to synthesize their own nutrients using cytoplasmic molecules c) accumulate nutrients inside the cell at higher concentrations than the external environment, which requires active transport mechanisms d) transport nutrients to the outside of the cell by facilitated diffusion
c) accumulate nutrients inside the cell at higher concentrations than the external environment, which requires active transport mechanisms
Nutrients can be concentrated from dilute solutions by _________. a) pinocytosis b) endocytosis c) active transport and group translocation d) electron transport
c) active transport and group translocation
An arrangement of microtubules located in the matrix of cilia and flagella is called the _________. a) axial bundle b) axial filament c) axoneme d) axillary tubule
c) axoneme
A fundamental difference between bacterial and archaeal membranes is that _________. a) the phospholipids in archaea are comprised of a glycerol molecule and three fatty acids vs. two fatty acids in bacteria b) archaeal membranes have a hydrophobic exterior and a hydrophilic interior vs. the reverse in bacterial membranes c) bacterial membranes are always comprised of phospholipid bilayers, whereas archaeal membranes can be bilayers or monolayers d) archaeal membranes must be able to solidify due to the extreme habitats the organisms occupy
c) bacterial membranes are always comprised of phospholipid bilayers, whereas archaeal membranes can be bilayers or monolayers
The organelle responsible for harvesting light as an energy source for photosynthesis is the _________. a) kinetoplast b) centriole c) chloroplast d) mitochondrion
c) chloroplast
The Golgi apparatus is comprised of flattened, saclike structures called _________, which may be clustered in one region or scattered throughout the cell. a) cristae b) thylakoids c) cisternae d) vesiculae
c) cisternae
The endoplasmic reticulum is composed of flattened sacs called _________. a) thylakoids b) cristae c) cisternae d) vacuomes
c) cisternae
Some archaea have been observed to form tubelike structures with tiny grappling hooks at the ends. These tubelike structures are called _________. a) flagella b) pili c) hami d) cannulae
c) hami
Protein filaments with a diameter of about 10 nm that are major components of the cytoskeleton are called _________. a) microtubules b) microfilaments c) intermediate filaments d) mycelia
c) intermediate filaments
Bacterial movement toward or away from a chemical is often described as a "random biased walk" due to the fact that _________. a) runs and tumbles occur more or less in equal amounts causing a random motion b) it still runs to change direction but it occurs less often than in the absence of a chemical, and tumbles more, creating an overall net motion in one direction c) it still tumbles to change direction but it occurs less often than in the absence of a chemical, and runs more, creating an overall net motion in one direction d) it still tumbles to change direction but it occurs more often than in the absence of a chemical, and runs less, creating an overall net motion in one direction
c) it still tumbles to change direction but it occurs less often than in the absence of a chemical, and runs more, creating an overall net motion in one direction
The movement of molecules from an area of higher concentration to an area of lower concentration without the participation of specific carrier molecules is called _________. a) facilitated diffusion b) osmosis c) passive diffusion d) active transport
c) passive diffusion
Certain white blood cells engulf microorganisms and bring them in to digest them. This process is best described as _________. a) pinocytosis b) receptor-mediated exocytosis c) phagocytosis d) diffusion e) osmosis
c) phagocytosis
A newly discovered unicellular microbe has a nucleus containing linear chromosomes and is surrounded by a membrane. It has mitochondria, 80s ribosomes, and is covered by cilia. There is no cell wall external to the plasma membrane. This organism most likely would be a/an _________. a) bacterium b) archaeon c) protozoan d) fungus e) algae
c) protozoan
The nucleolus plays a major role in synthesis of _________. a) mRNA b) tRNA c) rRNA d) transcription activation proteins
c) rRNA
The concept that living organisms arise from nonliving material is called _________ a) biogenesis b) cell theory c) spontaneous generation d) germ theory
c) spontaneous generation
Structural differences between Gram-positive and Gram-negative bacteria are observed following the Gram-staining procedure since _________. a) the thick layer of peptidoglycan in Gram-negative bacteria is dehydrated during the alcohol step, thus acting as an impermeability barrier retaining the purple stain b) the thin layer of peptidoglycan in Gram-positive bacteria is dehydrated during the alcohol step, thus acting as an impermeability barrier allowing the stain to wash out c) the thick layer of peptidoglycan in Gram-positive bacteria is dehydrated during the alcohol step, thus acting as an impermeability barrier retaining the crystal violet/iodine complex d) the thin layer of peptidoglycan in Gram-negative bacteria is dissolved during the alcohol step, thus acting as an impermeability barrier allowing the crystal violet/iodine complex to be retained
c) the thick layer of peptidoglycan in Gram-positive bacteria is dehydrated during the alcohol step, thus acting as an impermeability barrier retaining the crystal violet/iodine complex
The light reactions of photosynthesis, which form ATP and NADPH, take place in the _________. a) stroma b) cytoplasm c) thylakoid membrane d) nucleus
c) thylakoid membrane
Twitching motility involves _________. a) peritrichous flagella b) periplasmic flagella c) type IV pili d) monotrichous flagella
c) type IV pili
Which type of membrane transport is most important for nutrient acquisition in nutrient-poor environments? a) Simple diffusion b) Facilitated diffusion through channel proteins c) Facilitated diffusion through membrane carrier proteins d) Active transport
d) Active transport
According to the endosymbiosis hypothesis _________. a) the first endosymbiotic event involved an anaerobic bacterium b) the first endosymbiont was a fermentative organism c) the mitochondrion evolved from the same endosymbiont as the hydrogenosome d) All of the choices are correct.
d) All of the choices are correct.
Archaeal membranes contain which of the following lipids? a) Phospholipids b) Sulfolipids c) Glycolipids d) All of the choices are correct.
d) All of the choices are correct.
In order to distinguish them from bacterial flagella, archaeal flagella have been renamed as archaella because _________. a) archaean flagella are composed of more than one type of flagellin subunit b) archaean flagella are solid and not hollow c) some archaeon flagella don't have hooks they are more slender than bacterial flagella d) All of the choices are correct.
d) All of the choices are correct.
Microdomains in eukaryotic plasma membranes can participate in _________. a) cell movement b) cell division c) signal transduction d) All of the choices are correct.
d) All of the choices are correct.
The Archaea generally lack which of the following that are normally found in Gram-negative bacteria? a) Outer membrane b) A complex peptidoglycan network c) Lipopolysaccharide d) All of the choices are correct.
d) All of the choices are correct.
Which of the following are characteristics of hydrogenosomes that distinguish them from mitochondria? a) Hydrogenosomes generate ATP by fermentation. b) The inner membrane of hydrogenosomes is not highly folded. c) Hydrogenosomes have no DNA. d) All of the choices are correct.
d) All of the choices are correct.
Which of the following contribute(s) to the differences between the members of the Domain Archaea and the Domain Bacteria? a) Archaea lack muramic acid. b) Archaea have isopranyl glycerol ethers rather than fatty acid esters in their membrane lipids. c) Archaea differ from bacteria in their tRNA composition, ribosome structure, and antibiotic sensitivity. d) All of the choices are correct.
d) All of the choices are correct.
Which of the following is a function of the mitochondrion? a) Tricarboxylic acid cycle enzyme reactions b) Electron transport c) ATP synthesis d) All of the choices are correct.
d) All of the choices are correct.
Which of the following is/are true of capsules? a) They help bacteria escape phagocytosis by host cells. b) They retain water and help prevent desiccation of the bacteria. c) They prevent entry of many bacterial viruses. d) All of the choices are correct.
d) All of the choices are correct.
You are working with a newly described microorganism that has flagella that are solid, 10 nm in diameter, and composed of more than one type of flagellin subunit. Based on the type of flagella, which type of organism is this? a) Protozoa b) Bacteria c) Algae d) Archaea
d) Archaea
Why is boiling at standard temperature and pressure an inadequate method of processing for canned foods? a) Heat does not kill bacteria, ultraviolet radiation is the only effective method of processing. b) Boiling kills nonpathogenic bacteria but pathogenic bacteria will survive. c) Boiling kills C. botulinum bacteria but the exotoxin it produces remains potent. d) Boiling to 100°C will kill vegetative C. botulinum cells, but any spores will survive to temperatures of 120°C.
d) Boiling to 100°C will kill vegetative C. botulinum cells, but any spores will survive to temperatures of 120°C.
Prior to the work of _________, scientists did not distinguish between members of the Archaea and the Bacteria. a) Louis Pasteur b) John Tyndall c) Sergei Winogradsky d) Carl Woese
d) Carl Woese
Where is the glycolysis pathway located in a cell? a) Cristae of the mitochondria b) Matrix of the mitoconddria c) Smooth endoplasmic reticulum d) Cytoplasm
d) Cytoplasm
What is the most compelling reason why DNA, rather than RNA, evolved to be the storage repository for genetic information in cellular life forms? a) DNA molecules are larger than RNA molecules. b) DNA has deoxyribose rather than ribose. c) DNA is double-stranded rather than single-stranded. d) DNA molecules are more chemically stable than RNA molecules.
d) DNA molecules are more chemically stable than RNA molecules.
Which of the following statements about receptor-mediated endocytosis is true? a) It is used to transport material out of the cell b) None of the choices are correct. c) It involves transport of material into the cell through pores in the cell membrane d) It involves clathrin-coated pits e) It is not specific
d) It involves clathrin-coated pits
Which of the following cytoskeletal elements principally compose the eukaryotic flagella? a) Flagellin b) Actin filaments c) Intermediate filaments d) Microtubules
d) Microtubules
Which of the following is not a major class of growth factors? a) Amino acids b) Purines and pyrimidines c) Vitamins d) Nucleic acids
d) Nucleic acids
Which organelle is the primary location for the eukaryotic cell's DNA? a) Rough endoplasmic reticulum b) Golgi c) Mitochondria d) Nucleus
d) Nucleus
Which of the following statements is true regarding pili and flagella assembly? a) Pili grow when protein subunits are added to the tip, whereas flagellin proteins are added to the base of the flagella during growth. b) Pili and flagella are synthesized in a similar fashion; the proteins are produced internally then added to the base of the growing appendage. c) Pili and flagella are synthesized in a similar, complex manner; approximately 20 different proteins are made inside the cell then secreted to extend the tip of the appendage. d) Pili grow when protein subunits are added to the base, whereas flagellin proteins are added to the tip of the flagella during growth.
d) Pili grow when protein subunits are added to the base, whereas flagellin proteins are added to the tip of the flagella during growth.
To determine the relatedness of a new species of microbe to other species, genes that encode small subunit _________molecules are compared to determine the number of differences in the sequence. a) lipids b) DNA c) proteins d) RNA
d) RNA
What is bound to the rough endoplasmic reticulum that makes it different from the smooth endoplasmic reticulum? a) Mitochondria b) G-proteins c) Cytochrome proteins d) Ribosomes
d) Ribosomes
Which of the following is the most unique aspect of archaeon cell envelopes? a) The plasma membrane is composed of phospholipids. b) The cell walls contain a modified type of peptidoglycan. c) Archaeon capsules can be composed of protein or polysaccharide. d) Some archaeons have lipid monolayers in their plasma membrane.
d) Some archaeons have lipid monolayers in their plasma membrane.
Which statement correctly explains the Gram-stain reaction of archaeal cells? a) They are Gram-positive due to the pseudomurein layer in their cell walls. b) They are Gram-negative due to the lack of peptidoglycan in their cell walls. c) They don't stain - basic dyes used in the Gram stain don't adhere to archaeal cells. d) Some are Gram-positive and some are Gram-negative due to the diverse chemical structure.
d) Some are Gram-positive and some are Gram-negative due to the diverse chemical structure.
Which statement correctly describes archaeal cell walls? a) Some have an outer layer of complex polysaccharide. b) Some have an outer layer of protein. c) Many have peptidoglycan. d) Some have an outer layer of complex polysaccharide and some have an outer layer of protein.
d) Some have an outer layer of complex polysaccharide and some have an outer layer of protein.
Which cellular shape is seen among members of domain Bacteria that is not found among the domain Archaea? a) Cocci b) Bacilli c) Comma-shaped d) Spiral or corkscrew shapes
d) Spiral or corkscrew shapes
The rate of diffusion of a molecule into a cell is affected by which of the following factors? a) Same concentration of a molecule outside the cell as inside the cell b) Steep concentration gradient with a high amount of the molecule inside the cell c) Lower concentration of a molecule outside of the cell d) Steep concentration gradient with a high amount of the molecule outside the cell
d) Steep concentration gradient with a high amount of the molecule outside the cell
A strain of Neisseria gonorrhoeae has undergone a mutation and is no longer able to make pili. Predict the most likely outcome. a) The bacterial strain will no longer be able to transport certain sugars into the cell. b) The bacteria will become more virulent and will more readily establish infection. c) The bacteria will become more resistant to antibiotics. d) The bacteria will become less virulent and will not be able to readily establish infection.
d) The bacteria will become less virulent and will not be able to readily establish infection.
Select the correct statement about archaeal ribosomes. a) Archaeal ribosomal proteins are more similar to bacterial ribosomal proteins than to eukaryotic ribosomal proteins. b) Archaeal ribosomes are susceptible to antibiotics, similar to bacterial ribosomes. c) Archaeal ribosomes have subunits that are identical in shape and chemical components to those of bacteria. d) The chemical components of archaean ribosomes are more similar to those of eukaryotic ribosomes than to those of bacterial ribosomes.
d) The chemical components of archaean ribosomes are more similar to those of eukaryotic ribosomes than to those of bacterial ribosomes.
Which of the following is not true about archaeal ribosomes? a) They are 70S like bacterial ribosomes. b) Differences in rRNA nucleotide sequences led to the division of the prokaryotes into two separate taxa. c) They may possess ribosome binding sites homologous to bacterial Shine-Dalgarno sequences. d) They have similar antibiotic sensitivities to those of bacteria.
d) They have similar antibiotic sensitivities to those of bacteria.
A(n) ________ is a special type of lysosome used by a cell to selectively digest and recycle cytoplasmic contents, such as mitochondria. a) suicide vacuole b) turnover lysosome c) recycling vacuole d) autophagosome
d) autophagosome
Proteins function in modern cells as _________. a) catalysts b) hereditary information c) structural elements d) both catalysts and structural elements
d) both catalysts and structural elements
A feature unique to some archaeal plasma membranes is that they may _________. a) consist of a lipid bilayer that lacks integral membrane proteins b) consist of a lipid bilayer with embedded proteins c) contain sterols such as cholesterol d) consist of a lipid monolayer
d) consist of a lipid monolayer
Extracellular vesicles formed by Gram-positive cells are _________. a) peptidoglycan and plasma membrane surrounding the cytoplasm b) LPS, which surrounds the periplasm c) outer membrane, plasma membrane, and cytoplasm d) cytoplasm surrounded by plasma membrane
d) cytoplasm surrounded by plasma membrane
The cell membranes of archaeons that lack a cell wall are strengthened by _________. a) diglycerol ethers b) glycoprotein or protein layers c) pseudomurein d) diglycerol tetraethers
d) diglycerol tetraethers
The major site of cell membrane synthesis is the _________. a) nucleus b) plasma membrane c) lysosome d) endoplasmic reticulum
d) endoplasmic reticulum
The determination of the taxon to which an organism belongs is called _________. a) taxonomy b) classification c) systematics d) identification
d) identification
In eukaryotic cells, the enzymes involved in the tricarboxylic acid cycle (Kreb's cycle) are located _________. a) in the cytoplasm b) in the outer mitochondrial membrane c) in the inner mitochondrial membrane d) in the matrix of the mitochondria e) in the cristae
d) in the matrix of the mitochondria
Phagocytes are attracted by all of the following EXCEPT _________. a) components of the complement system b) phospholipids released by injured cells c) chemical products of microorganisms d) lysosomes
d) lysosomes
In endospore formation, when DNA condenses and aligns itself in the center of the cell, the cell is called a(n) _________. a) vegetative cell b) exosporangium c) forespore d) mother cell e) cortex
d) mother cell
In the Gram-positive bacterial cell wall, the tetrapeptides that extend from the peptidoglycan layers are linked by _________. a) a direct peptide bond b) fatty acid interbridges c) carbohydrate interbridges d) peptide interbridges
d) peptide interbridges
You are studying a newly discovered prokaryotic microorganism and are attempting to determine whether it will be classified in the domain Bacteria or in the domain Archaea. All of the following would be helpful in making that distinction except _________. a) sequence of small subunit ribosomal RNA b) type of membrane lipids c) presence or absence of peptidoglycan in cell walls d) presence or absence of double-stranded circular DNA genome
d) presence or absence of double-stranded circular DNA genome
Microbiology is being revolutionized by explorations in microbial genomics in all of the following ways except _________. a) how the genetic make-up of a microbial pathogen affects its ability to cause disease in the host b) the evolution of microbes is being genetically monitored c) the minimum number of genes required for independent survival is being determined d) the complex metabolic pathways of serovars are being compared
d) the complex metabolic pathways of serovars are being compared
The most important distinguishing feature of eukaryotes that is lacking in bacteria and archaea is _________. a) the presence of a cell wall in eukaryotes b) the cell respiration process which is fundamentally different in bacteria and archaea c) the DNA replication mechanism d) the division of the cell into compartments that are bound by membranes
d) the division of the cell into compartments that are bound by membranes
The first of Koch's postulates is _________. a) the suspected microorganisms must be isolated and grown in a pure culture b) the same microorganisms must be isolated from the diseased animal host c) animals infected with the isolated microorganism must develop the same disease d) the microorganism must be present in every case of the disease but absent from healthy organisms
d) the microorganism must be present in every case of the disease but absent from healthy organisms
Endospores are resistant to most environmental stressors because they have _________ _________complexed with calcium ions which stabilize DNA.
dipicolinic acid
Which of the following contribute to the environmental resistance of bacterial endospores? a) Spore coat b) Low water content of endospore c) Presence of calcium dipicolinate d) Lower pH e) All of the choices are correct.
e) All of the choices are correct.
Which types of eukaryotic cells have cell walls composed of cellulose? a) Algae b) Fungi c) Plants d) Protozoa e) Both algae and plants
e) Both algae and plants
Which mechanism of nutrient acquisition occurs in eukaryotes but is not seen in bacteria? a) Facilitated diffusion b) Active transport c) Group translocation d) Simple diffusion e) Endocytosis
e) Endocytosis
Receptor-mediated endocytosis _________. a) depends on the formation of clathrin-coated pits that pinch off b) is used to internalize molecules such as hormones, growth factors, iron, and cholesterol c) involves the formation of caveolae that are enriched in cholesterol and caveolin d) is typically used to internalize plasma membranes added by exocytosis e) depends on the formation of clathrin-coated pits that pinch off and is used to internalize molecules such as hormones, growth factors, iron, and cholesterol
e) depends on the formation of clathrin-coated pits that pinch off and is used to internalize molecules such as hormones, growth factors, iron, and cholesterol
Exocytosis is a process by which cells _________. a) bring in substances from the outside via pores in the cell membrane b) release substances from the cell via carrier proteins c) release substances from the cell through pores in the cell membrane d) bring in substances from the outside via vesicles e) release substances from the cell via vesicles
e) release substances from the cell via vesicles
Cilia beat with two distinctive phases. With the _________stroke, they stroke like an oar, thereby propelling the organism through the water. With the _________stroke, cilia bend along their length while they are pulled forward.
effective, recovery
Ribosomes synthesizing proteins that are to be excreted are located on the _________.
endoplasmic reticulum
Clostridium botulinum, which produces a toxin that causes botulism, is a major concern of the food industry due to its production of an extremely heat-resistant _________.
endospore
The most widely accepted current model for membrane structures is called the __________ ________model.
fluid mosaic
Capsules and slime layers are networks of polysaccharides that can extend from the bacterial surface. Both capsules and slime layers can be encompassed by the general term _________.
glycocalyx
The lysosome contains ________enzymes. anabolic hydrolytic photosynthetic alcoholic
hydrolytic
Intracellular granules of organic or inorganic material that are stockpiled by bacteria for future use are called _________.
inclusions
Although penicillin inhibits peptidoglycan synthesis, bacterial cells will continue to grow normally in the presence of penicillin in a(n) _________environment. hypotonic isotonic hypertonic nonpolar
isotonic
Archaea are cellular organisms that have unique cell membrane _________
lipids
The plasma membrane must possess mechanisms for getting nutrients into the cell. Nutrients such as oxygen and hydrogen are needed in relatively large amounts and are referred to as _________.
macroelements
Nutrients that are used by bacteria in relatively large amounts are _________.
macronutrients
The branch of microbiology that deals with diseases of humans and animals is called _________microbiology.
medical
The germination process of an endospore into a vegetative cell involves core enzymes becoming active due to increased water levels resulting in the ________ stage.
outgrowth
Elie Metchnikoff discovered _________, which is a major feature of the host immune response.
phagocytosis
Proteinaceous projections from the surface of a bacterium that are used to mediate conjugation are called sex _________, whereas projections that mediate attachment to surfaces such as host cells are called _________.
pili ; fimbriae
Bacteria that do not have a fixed shape are said to be _________.
pleomorphic
Cells with a relatively simple cell morphology that do not have a true membrane-delimited nucleus are called _________ prokaryotes eukaryotes urkaryotes nokaryotes
prokaryotes
The bacterial flagellum is driven to rotate by protons moving down a charge and pH gradient and the energy provided is called the __________ ______________ _________________.
proton motive force
Carl Woese distinguished between the members of the Archaea and the Bacteria using studies of their _________ DNA transfer RNA messenger RNA ribosomal RNA
ribosomal RNA
Many bacteria facilitate the uptake of iron by secreting low molecular weight molecules, called _________, to form complexes with the iron that can then be readily transported into the cell.
siderophores
A _________layer consists of diffuse unorganized polysaccharide material that lies outside the cell wall and is easily removed.
slime
A microbial _________ is a collection of strains that share many stable properties and differ significantly from other groups of strains.
species