Micro Chapter 3 Flashcards
Bacterial and Archaeal cells are similar in which of the following ways? A) Cell wall composition B) Plasma membrane lipids C) Cellular organization D) Cell envelope composition
C
Bacterial cells that grow in irregular groups and divide in random planes are characterized as A) Bacilli B) Pleomorphic C) Mycelia D) Staphylococci
D
Which of the following characteristics contributes to variation in bacterial and Archaeal size and shape? A) Surface area-to-volume ratio B) Presence of filamentous structures C) Cytoskeletal elements D) All of the above
D
Which of the following describes the layers of bacterial cellular organization (starting internally and working outward)?
A) Cytoplasm, plasma membrane, cell wall, capsule
B) Cytoplasm, cell wall, capsule, plasma membrane
C) Cytoplasm, plasma membrane, capsule, cell wall
D) Capsule, cytoplasm, cell wall, plasma membrane
A
What is the purpose of the nucleoid in bacterial and Archaeal cells?
A) Provides shape and protection from osmotic stress
B) Localization of genetic material
C) Buoyancy for floating in aquatic environments
D) Protein synthesis
B
The function of the plasma membrane in bacterial cells is to
A) Detect and respond to chemicals in the surrounding environment
B) Provide a selectively permeable barrier
C) Facilitate important metabolic processes
D) All of the above
D
Which of the following best describes current understanding of the fluid mosaic model of membrane structure?
A) Phospholipid monolayer with peripheral and integral membrane proteins
B) Phospholipid bilayer without membrane proteins
C) Phospholipid bilayer with peripheral and integral membrane proteins
D) Sphingolipid bilayer without membrane proteins
C
Hopanoids are important to bacterial cells because they likely A) Provide membrane stability B) Transport molecules into the cell C) Are involved in cell recognition D) Contribute to pathogenicity
A
Which of the following best describes the bacterial cell wall?
A) Protects the cell from osmotic lysis
B) Contributes to pathogenicity
C) Site of action of several antibiotics
D) All of the above
D
Most Gram-positive bacterial cells exhibit which of the following characteristics?
A) Thick layer of peptidoglycan without teichoic acids and large periplasmic space
B) Thick layer of peptidoglycan with teichoic acids and small periplasmic space
C) Thin layer of peptidoglycan without teichoic acids and large periplasmic space
D) Thin layer of peptidoglycan with techoic acids and a small periplasmic space
B
Most Gram-negative bacterial cells exhibit which of the following characteristics?
A) Thick layer of peptidoglycan without teichoic acids and large periplasmic space
B) Thick layer of peptidoglycan with teichoic acids and small periplasmic space
C) Thin layer of peptidoglycan without teichoic acids, large periplasmic space, and outer membrane
D) Thin layer of peptidoglycan with techoic acids, small periplasmic space, and outer membrane
C
The function of lipopolysaccharides (LPSs) on Gram-negative bacterial cells is to
A) Assist in evading the host immune response
B) Contribute to the negative charge on the cell surface
C) Create a permeability barrier
D) All of the above
D
Gram-positive cells stain purple because
A) Iodine binds with both crystal violet and safranin producing a purple color
B) Ethanol decolorizes the crystal violet from the cell
C) Ethanol shrinks the peptidoglycan pores and prevents loss of crystal violet
D) Safranin reacts with crystal violet producing a purple color
C
Human tears produce lysozyme, a hydrolytic enzyme that attacks peptidoglycan by hydrolyzing NAM-NAG bonds. If bacterial cells treated with lysozyme are placed into a hypotonic solution, what would be the result?
A) The cells would likely swell and lyse
B) The cell would likely shrink
C) The cells would likely become pleomorphic
D) Nothing
A
How do slime layers assist bacterial cells?
A) By resisting phagocytosis from host cells
B) By facilitating motility
C) By protecting against osmotic stress
D) All of the above
B
