Complete Test Bank Bacterial Cell Structure Ch.3 11e

Prescott's Microbiology, 11e (Willey)

Chapter 3 Bacterial Cell Structure

1) The genus of bacteria that undergoes cell division in random planes, forming grapelike clusters of round bacteria, are the ________.

2) Bacteria that do not have a fixed shape are said to be ________.

3) A branched network of hyphae formed by the Actinomycetes is called a __________.

4) Actinomycetes form long filaments called ________.

5) 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.

6) The cell membrane is a rigid structure that provides bacteria with their characteristic shapes.

7) Gram-positive bacteria have a thinner layer of peptidoglycan than Gram-negative bacteria.

8) Gram-positive bacteria have a structurally and chemically more complex cell wall than Gram-negative bacteria.

9) Bacteria growing at lower temperatures have more saturated fatty acids in their membranes.

10) Predict how the plasma membrane fatty acid composition would change as the temperature of the habitat of an aquatic bacterial species warms from 2oC to 15oC during the spring and summer months.

A) The percentage of saturated fatty acids would increase.

B) The percentage of unsaturated fatty acids would increase.

C) The percentage of saturated fatty acids would decrease.

D) The percentage of saturated fatty acids would remain unchanged.

11) When the cell wall is removed from a Gram-negative bacterium without removing the outer membrane, the resulting form is called a(n) ________.

12) Enzymes that are secreted out of the cell to aid in the acquisition and digestion of environmental nutrients are called ________.

13) Molecules or regions of molecules that readily interact with water are said to be ________, whereas molecules or regions of molecules that are insoluble in water or do not readily interact with water are said to be ________.

14) A ________ layer consists of diffuse unorganized polysaccharide material that lies outside the cell wall and is easily removed.

15) A ________ is a polysaccharide layer that lies outside the cell wall and is not easily removed.

16) ________ bind ferric iron and transport it into a bacterial cell.

17) Nutrients that are used by bacteria in relatively large amounts are ________.

18) Prokaryotes were once described based on structures that were present in eukaryotes, but absent in prokaryotes.

19) You discover a new transport system used by a newly discovered bacterial species. The sugars that are transported using this system are phosphorylated as they enter the bacterial cell. You would describe this transport system as a(n) ________.

A) facilitated diffusion

B) micronutrient regulator

C) passive diffusion

D) group translocation

20) Growth factors are molecules that cannot be synthesized by the bacteria that use them and include amino acids, pyrimidines, and vitamins.

21) Endospores are resistant to most environmental stressors because they have ________ ________ complexed with calcium ions which stabilize DNA.

22) Which of the following structures is NOT found in an endospore?

A) Capsule

B) Coat

C) Core

D) Exosporium

23) If you remove the peptidoglycan layer from a Gram-positive cell, it would still stain purple with a Gram stain.

24) The most widely accepted current model for membrane structures is called the ________ ________ model.

25) The layers of peptidoglycan of the bacterial cell wall can be cross-linked by peptide intrabridges or by direct cross-linking.

26) Some photosynthetic aquatic bacteria produce gas vacuoles that lack a lipid-bound membrane in order to regulate their buoyancy.

27) Intracellular granules of organic or inorganic material that are stockpiled by bacteria for future use are called ________.

28) Bacteria have a region of the cytoplasm known as the ________, which is not bounded by a membrane but contains the chromosome.

29) Small circular DNA molecules capable of replicating and containing genes that are useful but not necessary to the bacterium are called ________.

30) Some species of aquatic bacteria use inclusion bodies known as ________ to orient themselves in Earth's magnetic field.

31) ________ are the site of protein synthesis in the cell.

32) Sedimentation coefficients are proportional to the molecular weight of a particle and are not affected by the volume and shape of the particle.

33) 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.

34) 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 ________.

35) During the assembly of the flagellar filament, the flagellin protein monomers assemble from the base of the flagellum within the cell envelope.

36) The rotation of bacterial flagella is powered by ATP hydrolysis.

37) The bacterium E. coli swims in a straight line, called a ________, for a few seconds; then it stops, tumbles, then swims away in a new direction.

38) 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.

39) ________ is the process through which endospores are formed within a vegetative cell.

40) ________ is the main part of the process through which a vegetative cell is formed from an endospore.

41) The concept of a prokaryote was first fully outlined in 1962 by ________.

A) Watson and Crick

B) Stanier and Van Niel

C) Hershey and Chase

D) Gilbert and Cech

42) Bacterial cells that are variable in shape are called ________.

A) vibrio

B) pleomorphic

C) coccobacilli

D) hyphal

43) The term used to describe bacteria that are intermediate in shape between spherical and rod-shaped is ________.

A) cocci

B) bacilli

C) vibrio

D) coccobacilli

44) Square planar arrangement of cells that forms when round bacteria remain attached to each other during reproduction are called ________.

A) streptococci

B) staphylococci

C) tetrads

D) sarcinae

45) Flexible bacteria with a helical shape are called ________.

A) vibrios

B) spirilla

C) spirochetes

D) coccobacilli

46) Rigid bacteria with a helical cell shape are called ________.

A) vibrios

B) spirilla

C) spirochetes

D) coccobacilli

47) The term used to describe bacteria that are shaped like curved rods is ________.

A) coccus

B) bacillus

C) vibrio

D) coccobacillus

48) The term used to describe bacteria that are rod-shaped is ________.

A) coccus

B) bacillus

C) vibrio

D) coccobacillus

49) The term used to describe bacteria that have a spherical shape is ________.

A) coccus

B) bacillus

C) vibrio

D) coccobacillus

50) The cytoplasmic membrane of bacteria ________.

A) retains the cytoplasm and its contents

B) acts as a selectively permeable barrier, allowing some molecules to pass while preventing the movement of others

C) is the major site of ATP synthesis in aerobes

D) All of the choices are correct.

51) The lipopolysaccharide (LPS) that is found in the outer membrane of Gram-negative bacteria is also known as ________.

A) exotoxin

B) teichoic acid

C) murein

D) endotoxin

52) 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.

53) Proteins that are loosely associated with the cytoplasmic membrane are called ________ proteins.

A) peripheral

B) integral

C) external

D) internal

54) Proteins that are embedded within the cytoplasmic membrane and not easily extracted are called ________ proteins.

A) peripheral

B) integral

C) external

D) internal

55) 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

56) Lipids with polar and nonpolar ends are said to be ________.

A) amphipathic

B) amphibolic

C) bilateral

D) None of the choices are correct.

57) Although penicillin inhibits peptidoglycan synthesis, bacterial cells will continue to grow normally in the presence of penicillin in a(n) ________ environment.

A) hypotonic

B) isotonic

C) hypertonic

D) nonpolar

58) All of the following statements about the periplasmic space are true except ________.

A) it is found only in Gram-positive bacteria

B) it is located between the plasma membrane and outer membrane of Gram-negative bacteria

C) it contains hydrolytic enzymes and binding proteins involved in nutrient acquisition

D) a minimal periplasmic space may be observed between the plasma membrane and the peptidoglycan in some Gram-positive bacteria

59) 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

60) Sortase is a protein enzyme of bacteria that ________.

A) plays a key role in directing proteins to the periplasm

B) catalyzes covalent attachment of some surface proteins to peptidoglycan

C) directs secretion of proteins across the outer membrane

D) functions by transporting flagellum proteins to their extracellular site of assembly

61) Which of the following is not true of bacterial plasmids?

A) They can replicate independently of the chromosome.

B) They may carry genes for drug resistance.

C) They are required for host growth and/or reproduction.

D) They may carry genes that enhance survival of the bacterium under certain conditions.

62) Bacterial and archaeal ribosomes are known as ________ ribosomes, based on their sedimentation coefficient.

A) 50S

B) 30S

C) 80S

D) 70S

63) The type III bacterial protein secretion machinery ________.

A) has a needlelike structure through which proteins are secreted

B) includes structural features that may be evolutionarily related to the basal bodies of bacterial flagella

C) is found in Gram-negative bacteria

D) All of the choices are correct.

64) Export of flagellin subunits is mediated by ________.

A) an apparatus in the basal body of the flagellum that is related to the type II secretion pathway

B) the type I secretion pathway

C) an apparatus in the basal body of the flagellum that is related to the type III secretion pathway

D) None of the choices are correct.

65) The power used by most bacterial flagellar motors is produced by ________.

A) synthesis of glucose

B) ATP hydrolysis

C) proton motive force (PMF)

D) All of the choices are correct.

66) 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

67) Twitching motility involves ________.

A) peritrichous flagella

B) periplasmic flagella

C) type IV pili

D) monotrichous flagella

68) Endospores represent a challenge to the fields of industrial and medical microbiology because ________.

A) they are resistant to harsh environments, thus allowing survival of endospore-forming organisms under conditions in which non-endospore-forming cells would not survive

B) endospore-forming organisms are often dangerous pathogens

C) endospores are significantly smaller than vegetative cells

D) endospores are resistant to harsh environments, thus allowing survival of endospore-forming organisms under conditions in which non-endospore-forming cells would not survive, and endospore-forming organisms are often dangerous pathogens

69) Elements that are required in relatively large amounts by microorganisms are called ________.

A) multivitamins

B) meganutrients

C) macronutrients

D) macromolecules

70) Which of the following is not considered a macronutrient?

A) Carbon (C)

B) Calcium (Ca)

C) Potassium (K)

D) Cobalt (Co)

71) Which of the following is not considered a micronutrient?

A) Manganese (Mn)

B) Magnesium (Mg)

C) Zinc (Zn)

D) Copper (Cu)

72) The trace amounts of micronutrients needed by microorganisms are usually supplied as inadvertent contaminants in water and regular media components.

73) Zinc (Zn) is considered a macronutrient.

74) Copper (Cu) is considered a micronutrient.

75) Sulfur can be obtained from inorganic sources only.

76) Phosphorus can be obtained from organic sources only.

77) Nitrogen can be obtained from either organic or inorganic sources.

78) ________ ________ are required organic compounds because they are essential cell components or precursors of such components that cannot be synthesized by the organism.

79) Which of the following is not a major class of growth factors?

A) Amino acids

B) Purines and pyrimidines

C) Vitamins

D) Nucleic acids

80) Small organic molecules called ________ function as enzyme cofactors.

81) A wide variety of microorganisms are commercially used to manufacture ________ for human consumption.

A) sugars

B) vitamins

C) fatty acids

D) None of the choices are correct.

82) 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.

83) Transport of two different substances can be linked. If the transport is in the same direction it is called ________; if the transport is in opposite directions it is called ________.

84) ________ are carrier proteins embedded in the membrane that increase the rate of diffusion of specific molecules across selectively permeable membranes.

85) Organisms usually have only a single transport system for any nutrient.

86) Different transport systems for the same nutrient that are part of the same organism are usually regulated in different ways.

87) Permease proteins that aid in the transport of nutrients resemble enzymes in their specificity for the substance to be transported. Each carrier is selective and will transport only a closely related set of substances.

88) The extreme insolubility of ferric iron leaves little free iron available for transport into bacterial cells.

89) Which of the following processes can be used to bring nutrients into a cell against a concentration gradient?

A) Active transport

B) Facilitated diffusion

C) Passive diffusion

D) Active transport and facilitated diffusion

90) Which of the following is a characteristic of active transport?

A) Saturable uptake rate

B) Use of ATP or a proton gradient as a source of metabolic energy

C) Can move materials against a concentration gradient

D) All of the choices are correct.

91) The movement of molecules across a membrane from an area of lower concentration to an area of higher concentration with the expenditure of energy is called ________.

A) facilitated diffusion

B) osmosis

C) passive diffusion

D) active transport

92) The movement of molecules across a membrane from an area of higher concentration to an area of lower concentration with the use of a carrier molecule embedded in the membrane is called ________.

A) facilitated diffusion

B) osmosis

C) passive diffusion

D) active transport

93) 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

94) Nutrients can be concentrated from dilute solutions by ________.

A) pinocytosis

B) endocytosis

C) active transport and group translocation

D) electron transport

95) ________ membranes allow some molecules to pass but not others.

A) Permeable

B) Inverted monolayer

C) Selectively permeable

D) Impermeable

96) Motile bacteria have been placed in an environment with a gradient of a chemical attractant. Which of the following behaviors would you predict?

A) Bacteria will randomly switch back and forth between runs and tumbles.

B) The bacteria will only exhibit runs away from the chemical.

C) The bacteria will reduce tumbling frequency.

D) The bacteria will reduce run duration in the direction of the chemical.

E) The bacteria will both reduce tumbling frequency and increase run duration in the direction of the chemical.

97) Order the following structures (layers) that a small molecule must pass through as it moves from outside of an encapsulated Gram-negative cell to the cytoplasm.

1. Capsule

2. Outer membrane

3. Periplasm and Peptidoglycan

4. Plasma membrane

98) How do spheroplasts and protosplasts differ?

A) Spheroplasts retain the peptidoglycan but protoplasts do not.

B) Spheroplasts retain their outer membrane but protoplasts do not.

C) There is no difference; these terms are synonyms.

D) Spheroplasts form from cocci and protoplasts form from bacilli.

99) 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.

100) Which of the following statements is false regarding why some scientists believe that the term "prokaryote" is a somewhat artificial designation?

A) Some bacteria have internal membranous structures

B) Some bacteria have their genetic material enclosed within a membrane

C) Some bacteria have 80S ribosomes

D) Many bacteria have cytoskeletal elements

101) 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.

102) Predict the change in surface area and volume of a spherical cell if the diameter of the cell doubles.

A) The surface area will increase by a factor of 4, while the volume will increase by a factor of 8.

B) The surface area will increase by a factor of 8 while the volume will increase by a factor of 4.

C) The surface area and volume will both increase by a factor of 4.

D) The surface area will increase by a factor of 2 and the volume will increase by a factor of 4.

103) A new protein has been described that transports a growth factor across the plasma membrane. This protein is most likely a(n) ________.

A) peripheral membrane protein, facing outward

B) peripheral membrane protein, facing the cytoplasmic side

C) integral membrane protein

D) cytoplasmic protein

104) Endotoxic shock, resulting from the release of endotoxin by bacteria infecting a patient, is only caused by Gram-negative bacteria.

105) Place the steps of sporulation in the correct order.

1. Replication of DNA

2. In-folding of the plasma membrane to enclose a copy of DNA, forming forespore and septum

3. Engulfment of the forespore with a second membrane

4. Deposition of spore cortex

5. Spore coat formation

6. Maturation and release of endospore

106) Endospores are reproductive structures.

107) The original differentiation of prokaryotes and eukaryotes was based on structures found in prokaryotes that are lacking in eukaryotes.

108) Which bacterial structure may survive if temperatures applied during food preservation processes are too low?

A) Flagella

B) Endospores

C) Plasma membranes

D) Ribosomes

109) 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.

110) Which of the following is not part of the process by which an endospore transforms to become a vegetative cell?

A) Germination

B) Activation

C) Induction

D) Outgrowth

111) 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-positive bacteria is dehydrated during the alcohol step, thus acting as an impermeability barrier retaining the crystal violet/iodine complex

B) 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

C) 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

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

112) Which of the following statements is false regarding the differences between bacterial and eukaryotic cytoskeletal proteins?

A) Eukaryotic cells have cytoskeletal fibers comprised of tubulin and actin proteins, whereas bacterial cells lack cytoskeletal proteins.

B) Proteins in the cytoplasm of bacterial cells are structurally similar to the tubulin and actin found in eukaryotic cells.

C) Cytoskeletal proteins in both eukaryotes and bacteria function in cell division, protein localization and determination of cell shape.

D) The bacterial protein FtsZ is a homologue of the eukaryotic protein tubulin, and MreB and Mbl are homologues of actin.

113) Discovery of the bacterial cytoskeletal protein FtsZ provided an important link in the evolution of cells since ________.

A) is was also discovered in mitochondria and chloroplasts

B) it is unrelated to any eukaryotic proteins

C) it has no known function

D) it is only present in E. coli

Match the flagellar definition with the appropriate word

A) a cluster of flagella at one or both ends of an organism

B) a single flagellum

C) a single flagellum at each pole of an organism

D) a relatively even distribution of flagella over the entire surface of the bacterium

114) monotrichous

115) peritrichous

116) amphitrichous

117) lophotrichous