Mastering Microbiology ch. 4

Which of the following scenarios is an example of bacterial motility? a. A bacterium being removed from the skin during hand washing b. A bacterium traveling through the air from a sneeze c. A bacterium moving towards a food source

c. A bacterium moving towards a food source

What is the advantage to spirochetes of the corkscrew movement provided by axial filaments? a. It provides faster movement, allowing the spirochete to escape the cells of the immune system. b. It hides the flagella, so they are not as easily detected by the immune system. c. It allows the cells to move more easily through viscous human tissues and fluids, such as mucus. d. It makes spirochete cells more flexible, and prevents them from breaking as easily as bacillus-shaped bacteria.

c. It allows the cells to move more easily through viscous human tissues and fluids, such as mucus.

Which of the following statements regarding active transport is false? a. It requires the use of a transport protein. b. It requires ATP. c. It powers the diffusion of water across the cell membrane.

c. It powers the diffusion of water across the cell membrane.

The basal body is comprised of which structural component(s) of flagella? a. Rod b. Filament c. Rod and Rings d. Rings e. Rod and Hook f. Hook

c. Rod and Rings

What type of transport uses two transport proteins? a. Uniport b. Antiport c. Symport d. None of the proteins do e. All of the proteins do

c. Symport

What will happen to a cell that is placed in a solution containing a high concentration of sugar, a molecule that cannot pass across the cell membrane? a. The cell will swell up with water and burst. b. The cell will pump the salt in the cytoplasm out of the cell via simple diffusion. c. The cell will lose its interior water, causing it to shrivel up and possibly die.

c. The cell will lose its interior water, causing it to shrivel up and possibly die.

Why are ATPases associated with active transport proteins? a. They allow for the production of ATP that is needed during active transport. b. They help pump phosphate ions across the membrane to maintain the electrochemical gradient. c. They provide transport proteins with the energy needed to pump molecules against their concentration gradients. d. They are important only in symport proteins, because two are required. e. All of the above

c. They provide transport proteins with the energy needed to pump molecules against their concentration gradients.

Efflux pumps can be used to pump antibiotics out of a cell once they enter to protect the cell. This will be done against the concentration gradient of the antibiotic. Which of the active transports would most likely be used? a. Symport b. Antiport c. Uniport

c. Uniport

How is osmosis different from simple diffusion? a. Water cannot pass freely across the membrane. b. Water requires energy to move across a cytoplasmic membrane. c. Water movement is driven by the concentration of solutes rather than its own concentration. d. Water requires a special permease.

c. Water movement is driven by the concentration of solutes rather than its own concentration.

Many pathogenic bacteria produce a(n)________ that protects them from phagocytosis by host cells a. flagellum b. pilius c. capsule d. endospore

c. capsule

Which of the following is part of the endomembrane system? a. mitochondria b. ribosomes c. flagellum d. cytoskeleton e. Golgi apparatus

e. Golgi apparatus

Which of the following types of bacterial cells would have flagella located at only one end of the cell? a. Monotrichous and amphitrichous b. Lophotrichous c. Amphitrichous d. Monotrichous e. Lophotrichous and monotrichous f. Peritrichous

e. Lophotrichous and monotrichous

Eukaryote

- nucleus - rough endoplasmic reticulum - golgi complex - mitochondria

Prokaryote

- capsule

Prokaryote and Eukaryote

- flagella - plasma membrane - cytoplasm - ribosomes

Which of the following statements is TRUE? a. Endospores allow a cell to survive environmental changes by producing a dormant period with no growth. b. A cell produces one endospore and keeps growing. c. Endospores are easily stained in a Gram stain. d. Endospores are for reproduction. e. A cell can produce many endospores.

a. Endospores allow a cell to survive environmental changes by producing a dormant period with no growth.

Which of the following is NOT true of the gram-negative outer membrane? a. It contains enzymes for energy synthesis b. It has polysaccharide antigens that are useful in bacterial identification c. It contains lipids also known as endotoxins d. It is part of the gram-negative cell wall e. It contains lipopolysaccharide

a. It contains enzymes for energy synthesis

How is simple diffusion different from other types of passive transport? a. Simple diffusion does not require a permease. b. Simple diffusion requires ATP. c. Simple diffusion only brings material into the cell, not out of it. d. Simple diffusion is only the diffusion of water.

a. Simple diffusion does not require a permease.

Antibiotics that target the cell wall are an effective treatment against many pathogenic bacteria. a. True b. False

a. True

Small, hydrophobic molecules pass through a cell membrane most easily by diffusion. a. True b. False

a. True

The cell walls of bacteria are responsible for the shape of the bacteria and the difference in the Gram stain reaction. a. True b. False

a. True

The internal structure of eukaryotic cilia and flagella are the same. a. True b. False

a. True

Which of the following is NOT a typical characteristic of most bacterial plasma membranes? a. contains cholesterol b. is selectively permeable c. composed of a phospholipid bilayer d. site of energy production e. contains proteins

a. contains cholesterol

Which of the following organelles most closely resembles a prokaryotic cell? a. mitochondrion b. vacuole c. cell wall d. Golgi complex e. nucleus

a. mitochondrion

As a bacterium approaches a food source, one would expect a. runs to become more frequent. b. flagella to stop spinning. c. tumbles to become more frequent. d. flagella to rotate clockwise more frequently.

a. runs to become more frequent.

Consider a gram-positive cell in a hypertonic medium. If the peptidoglycan were damaged, the cell would______ a. shrink b. remain the same size c. swell d. shrink and then swell

a. shrink

Axial filaments are found on a. spirochetes. b. rod-shaped bacilli. c. staphylococci. d. streptococci.

a. spirochetes.

The terms "run" and "tumble" are generally associated with a. taxic movements of the cell in response to attractants or repellents. b. cell membrane synthesis. c. clustering properties of certain rod-shaped bacteria. d. cell wall fluidity.

a. taxic movements of the cell in response to attractants or repellents.

Hydrophobic molecules would enter a cell a. through integral transport proteins. b. by passive transport directly across the membrane. c. by active transport directly across the membrane.

a. through integral transport proteins.

How are Gram-positive and Gram-negative flagella different? a. Flagella are only found in Gram-negative bacteria. b. A Gram-positive flagellum has only two rings in its basal body; Gram-negatives each have four. c. A Gram-positive flagellum does not have a membrane covering its filament; A Gram-negative flagellum does. d. Each Gram-positive flagellum contains a hook; gram-negatives do not.

b. A Gram-positive flagellum has only two rings in its basal body; Gram-negatives each have four.

Sodium and potassium ions need to be pumped simultaneously against their concentration gradients. Which one of the transport proteins would be most effective at this? a. Uniport b. Antiport c. Symport d. Any would work, as they can all pump ions out.

b. Antiport

How does water enter and exit a cell? a. By use of an integral transport protein b. By simple diffusion or by use of an integral transport protein c. By simple diffusion across the membrane d. By use of a peripheral transport protein

b. By simple diffusion or by use of an integral transport protein

Cells placed in a hypotonic solution tend to lose water due to osmotic pressure. a. True b. False

b. False

You are observing a Gram stain of rod-shaped microorganisms that are linked in a chain and stain purple. How would you describe these bacteria using the correct terminology for the cell shaped and arrangement? a. Gram-positive tetrads b. Gram-positive streptobacilli c. Gram-positive coccobacilli d. Gram-negative staphylococci

b. Gram-positive streptobacilli

Which of the following types of bacterial cells would have only a single flagellum? a. Amphitrichous b. Monotrichous c. Peritrichous d. Lophotrichous e. Lophotrichous and monotrichous

b. Monotrichous

Which of the active transport types employs diffusion? a. Antiport b. Symport c. Uniport and Antiport d. All types of active transport make use of some form of diffusion. e. Uniport

b. Symport

How do axial filaments differ from regular bacterial flagella? a. They do not rotate. b. The axial filament is located between the cell membrane and the outer membrane. c. They do not function in cell movement.

b. The axial filament is located between the cell membrane and the outer membrane.

What will occur if a bacterial cell with a weakened or damaged cell wall is placed in pure water? a. The cell will remain the same size b. The cell will swell and burst c. The cell will form endospores d. The cell will shrink e. The cell will form a new cell wall

b. The cell will swell and burst

Why are receptors on the cell surface necessary for bacterial movement? a. The receptors actually spin the flagella. b. The receptors sense the stimulus and send signals to the flagella. c. The bacterium contains receptors that are sensitive to light. d. The receptors physically alter shape to steer the bacterium.

b. The receptors sense the stimulus and send signals to the flagella.

Which of the following statements about gram-negative cell walls is FALSE? a. They have an extra outer layer composed of lipoproteins, lipopolysaccharides, and phospholipids. b. They are sensitive to penicillin. c. Their Gram reaction is due to the outer membrane. d. They protect the cell in a hypotonic environment. e. They are toxic to humans.

b. They are sensitive to penicillin.

Nonspecific permeases a. are not used for passive transport. b. allow a variety of molecules to cross the cytoplasmic membrane. c. allow only one type of solute to pass through the membrane. d. allow only water to cross the cytoplasmic membrane.

b. allow a variety of molecules to cross the cytoplasmic membrane.

The rings a. are curved structures into which each filament inserts. b. anchor the flagellum to the cell membrane. c. are comprised of globular proteins called flagellin. d. are covered by a membrane.

b. anchor the flagellum to the cell membrane.

Pathogenic bacteria a. do not have flagella. b. can be identified and classified by differences in their flagellar proteins. c. have a unique basal body structure. d. are unique because they have a membrane covering the filament.

b. can be identified and classified by differences in their flagellar proteins.

Axial filaments are composed of a. the outer membrane. b. endoflagella. c. axial fibers.

b. endoflagella.

Penicillin specifically interferes with peptidoglycan synthesis. Which of the following cells is most likely to be damaged by penicillin? a. Human cells b. Gram-positive bacterial cells c. yeast cells d. cells of archaea

b. gram-positive bacterial cells

You are observing a Gram stain of spherical-shaped microorganisms that are linked in a chain and stain purple. How would you describe these bacteria using the correct terminology for the cell shape and arrangement? a. gram-negative staphylococci b. gram-positive streptococci c. gram-positive coccobacilli d. gram-positive tetrads

b. gram-positive streptococci

You have isolated a motile, gram-positive cell with no visible nucleus. You can safely assume that the cell a. has a mitochondrion. b. has a cell wall. c. lives in an extreme environment. d. has cilia. e. has 9 pairs + 2 flagella.

b. has a cell wall.

Which of the following organelles breaks down worn-out organelles? a. Golgi apparatus b. lysosomes c. smooth endoplasmic reticulum (ER) d. rough endoplasmic reticulum (ER) e. mitochondria

b. lysosomes

Integral proteins are mostly involved in a. enzymatic function. b. transport function. c. recognition sites. d. receptors.

b. transport function.

Which of the following is NOT characteristic of the glycocalyx found in bacteria? a. a structure that can be visualized using an acidic negative stain and a basic counterstain b. if firmly attached, contributes to bacterial virulence c. creates a slimy, slippery coating that prevents bacteria from attaching to surfaces d. a viscous coating surrounding the cell made of polysaccharide, polypeptide, or both

c. creates a slimy, slippery coating that prevents bacteria from attaching to surfaces

The structural framework in a cell is the a. extracellular matrix. b. endoplasmic reticulum (ER). c. cytoskeleton. d. plasma membrane. e. endomembrane system

c. cytoskeleton.

All of the following are found in the cell walls of gram-positive bacteria EXCEPT_______ a. peptidoglycan b. teichoic acid c. lipid A d. N-acetylglucosamine e. lipoteichoic acid

c. lipid A

Where in a cell is ATP made? a. chloroplasts b. ribosomes c. mitochondria d. nucleus e. lysosomes

c. mitochondria

Where is the genetic information of the cell stored? a. lysosomes b. smooth endoplasmic reticulum (ER) c. nucleus d. Golgi apparatus e. rough endoplasmic reticulum (ER)

c. nucleus

Antibiotics that target cell wall synthesis ultimately cause bacterial cell death as a result of a. plasmolysis. b. decreased synthesis of plasma membrane. c. osmotic lysis. d. inhibition of molecular transport. e. cell shrinkage.

c. osmotic lysis.

One of the ways smooth endoplasmic reticulum (ER) differs from rough endoplasmic reticulum is that rough ER is covered by a. the extracellular matrix. b. the Golgi apparatus. c. ribosomes. d. the cytoskeleton. e. mitochondria.

c. ribosomes.

Gram-negative cells contain a periplasmic space that is __________ a. a site of endocytosis b. filled with lysozyme c. rich in degradative enzymes d. abundant in teichoic acid e. the site of protein synthesis

c. rich in degradative enzymes

Peritrichous bacteria make a run when a. the flagella turn clockwise and become bundled. b. the flagella turn counterclockwise and separate. c. the flagella turn counterclockwise and become bundled. d. the flagella turn clockwise and separate.

c. the flagella turn counterclockwise and become bundled.

Where are phospholipids most likely found in a prokaryotic cell? a. the plasma membrane and around organelles b. around organelles c. the plasma membrane d. ribosomes e. flagella

c. the plasma membrane

A positively charged sodium ion a. would get stuck in the hydrophobic core of the membrane. b. freely diffuses directly across the cell membrane. c. would require the use of integral protein channels to pass through a cell membrane.

c. would require the use of integral protein channels to pass through a cell membrane.

What structural part of a bacterial flagellum is composed of flagellin? a. Rod b. Basal body c. Hook d. Filament

d. Filament

Which of the following statements about bacterial flagella is true? a. Bacteria can only rotate flagella clockwise. b. Flagella work by undulating. c. Bacteria can only rotate flagella counterclockwise. d. Flagella can rotate 360 degrees.

d. Flagella can rotate 360 degrees.

Which of the following molecules would be blocked by a cell membrane? a. Simple alcohols b. Water c. Dissolved oxygen d. Ions

d. Ions

Which of the following statements about a gram-negative cell wall is FALSE? a. It maintains the shape of the cell b. It includes a thin layer of peptidoglycan c. It functions as an endotoxin d. It contains teichoic acid

d. It contains teichoic acid

What is a hallmark of passive transport across cell membranes? a. It requires the use of ATP. b. It occurs along an electrochemical gradient. c. It cannot occur without assistance from an integral membrane protein. d. It occurs along an electrochemical gradient, and may involve the use of transport proteins. e. It may involve the use of transport proteins.

d. It occurs along an electrochemical gradient, and may involve the use of transport proteins.

With a light microscope, which of the following would allow discrimination between eukaryotes and prokaryotes? a. Observation of photosynthetic pigment b. Observation of flagella c. Observation of the plasma membrane d. Observation of nuclei d. Observation of the ribosomes

d. Observation of nuclei

Which of the following terms refers to a bacterium moving towards a light source? a. Negative phototaxis b. Negative chemotaxis c. Positive chemotaxis d. Positive phototaxis

d. Positive phototaxis

What makes phospholipid membranes good at keeping some molecules out, and allowing others to freely pass? a. They are positively charged. b. They are completely hydrophobic. c. They are completely hydrophilic. d. They have both hydrophilic and hydrophobic regions.

d. They have both hydrophilic and hydrophobic regions.

Which membrane transport mechanism requires ATP? a. facilitated diffusion b. simple diffusion c. osmosis d. active transport

d. active transport

A Gram stain of a wound reveals purple, spherical bacteria that divide and remain attached in grapelike clusters. These are referred to as a. gram-positive streptococci b. gram-negative spirochetes c. gram-positive tetrads d. gram-positive staphylococci

d. gram-positive staphylococci

A glycoprotein a. can be used as a receptor. b. can be used in enzymatic functions. c. is a type of peripheral protein. d. is a type of peripheral protein above that can be used as a receptor or in enzymatic functions.

d. is a type of peripheral protein above that can be used as a receptor or in enzymatic functions.

Taxis is a. another term for bacterial tumbling. b. caused by the undulating motion of a bacterium. c. another word for stimulus. d. movement towards or away from a stimulus.

d. movement towards or away from a stimulus.

Why is penicillin selectively toxic to bacterial cells but harmless to human cells? a. Penicillin is inactivated within lysosomes of human cells c. The glycocalyx of an animal cell provides a barrier through which penicillin cannot pass d. Penicillin specifically weakens peptidoglycan, which is found only in bacterial cells e. Human cells actively transport penicillin out of the cell

d. penicillin specifically weakens peptidogylcan, which is found only in bacterial cells

Tumbles occur when a. the flagella rotate counterclockwise. b. the flagella stop rotating. c. the flagella undulate. d. the flagella rotate clockwise.

d. the flagella rotate clockwise.

Functions of the glycocalyx include all of the following EXCEPT a. source of nutrition. b. biofilm formation. c. protection against dehydration. d. increased virulence. e. binary fission.

e. binary fission.

Which of the following pairs is mismatched? a. mitochondria ATP production b. endoplasmic reticulum internal transport c. lysosome digestive enzymes d. Golgi complex secretion e. centrosome food storage

e. centrosome food storage

Which of the following is NOT a structure of prokaryotic cells? a. Flagellum b. Chromosome c. Ribosome d. Capsule e. Chloroplast

e. chloroplast

What carries instructions for making proteins from the nucleus into the cytoplasm? a. ATP b. ribosomes c. DNA d. Rough ER e. mRNA

e. mRNA

What structure acts as a selective barrier, regulating the traffic of materials into and out of the cell? a. nuclear envelope b. endomembrane system c. cytoskeleton d. extracellular matrix e. plasma membrane

e. plasma membrane

Where are lipids made in the cell? a. Golgi apparatus b. ribosomes c. mitochondria d. rough endoplasmic reticulum (ER) e. smooth endoplasmic reticulum (ER)

e. smooth endoplasmic reticulum (ER)