Deck 4: An Introduction to Cell Structure and Host-Pathogen Relationships

Question 1

Organisms that can cause disease only if they exploit a host's decreased resistance to infection and disease are referred to as

A)Auto-inducers
B)Opportunists
C)Primary pathogens
D)Mutualistic pathogens
E)Quorum sensors

Answer 1

Opportunists

Question 2

Which of the following is not a spherical bacterium?

A)Streptococci
B)Streptobacilli
C)Tetrads
D)Staphylococci
E)Diplococci

Answer 2

Streptobacilli

Question 3

An outbreak of food poisoning occurs at a family picnic after the growth of Staphylococcus aureus in unrefrigerated potato salad left sitting in the hot sun for several hours.What would microscopic examination of the potato salad reveal?

A)Long chains of cocci
B)Diplococcic
C)Tetrads
D)Clusters of cocci
E)Spirillum

Answer 3

Clusters of cocci

Question 4

Which of the following is a mismatched pair?

A)Primary pathogen; disease in uncompromised host
B)Pathogenicity islands; virulence gene clusters
C)Environmental surveillance; quorum sensing
D)Biofil;E. coli
E)Opportunistic; disease in compromised host

Question 5

Which bacteria lose their crystal violet when the decolorizer alcohol is added during the Gram stain procedure?

A)Gram-negative
B)Gram-positive
C)Gram-intensive
D)Gram-dormant

Question 6

An appropriate stain for a sputum sample from a patient with tuberculosis is the _____ stain.

A)Gram
B)Flagella
C)Acid-fast
D)Endospore
E)Negative

Question 7

An organism whose cells lack a nucleus and other membrane-bound structures is a (n)

A)Organelle
B)Eukaryote
C)Human
D)Prokaryote
E)Plasmid

Question 8

Which of the following is not an example of a differential stain?

A)Endospore stain
B)Gram stain
C)Acid-fast stain
D)Simple stain
E)Flagella stain

Question 9

Which of the following explains why it is necessary to use safranin in the Gram stain?

A)Gram-positive bacteria do not have a strong affinity for crystal violet, but do bind well to safranin
B)Gram-negative bacteria are rendered colorless after the decolorizer is added, and need to be counterstained to be visible under the microscope
C)Safranin is the mordant needed to set the crystal violet color and make it permanent
D)Gram-variable cells do not bind to crystal violet and need to be counterstained to be visible under the microscope
E)None of the choices are true

Question 10

Which of the following statements is false?

A)Bacteria that have a capsule are able to resist host defense mechanisms
B)To view a flagellum under a conventional microscope it is necessary to coat it with layers of dye or metals
C)Acid-fast bacteria stain equally well with the acid-fast stain and the Gram stain
D)Only bacteria containing mycolic acid in their cell wall are acid-fast
E)The decolorizer in the acid-fast stain is acid

Question 11

What is the function of a flagellum?

A)Resistance to antibodies
B)Motility
C)Resistance to antibiotics
D)Resistance of disinfectants
E)Endospore formation

Question 12

In the Gram stain,_____ is used as a mordant to stabilize crystal violet in _____ cells.

A)Alcohol; Gram-positive
B)Alcohol; Gram-negative
C)Iodine; Gram-positive
D)Iodine; Gram-negative
E)Safranin; Gram-nonreactive

Question 13

What are spiral-shaped rigid bacteria?

A)Fusiform bacilli
B)Spirillum
C)Streptobacilli
D)Spirochetes
E)Pleomorphic

Question 14

Which of the following increases susceptibility to infection?

A)Malnutrition
B)Poverty
C)Crowded housing conditions
D)Unsanitary conditions
E)All of the choices

Question 15

What is used for the purpose of viewing the shape and arrangement of bacteria and employs a single basic dye?

A)Simple stain
B)Endospore stain
C)Negative stain
D)Acid-fast stain
E)Differential stain

Question 16

Which of the following does not differentiate Gram-positive from Gram-negative organisms?

A)Multilayered peptidoglycan versus thin peptidoglycan
B)No membrane outside cell wall versus membrane outside cell wall
C)Presence of polysaccharide versus absence of polysaccharide
D)Rich in exotoxin versus rich in endotoxin
E)After iodine treatment retains crystal violet versus does not retain crystal violet

Question 17

Which of the following is not an example of a basic dye and is repelled by capsules?

A)Methylene blue
B)Nigrosine
C)Safarin
D)Crystal violet
E)Carbolfuchsin

Question 18

Bacteria which are spherical are

A)Bacilli
B)Coccobacilli
C)Fusiform bacilli
D)Spirillum
E)Cocci

Question 19

A patient has been diagnosed with gonorrhea.Which of the following would be seen microscopically when examining the patient's sample?

A)Streptococci
B)Diplococci
C)Coccobacilli
D)Tetrads
E)Staphylococci

Question 20

Flagella are very difficult to observe microscopically because

A)They are very thin
B)They resist basic dyes
C)They resist acidic dyes
D)They do not adhere to glass slides

Question 21

Explain why a high mortality (death)rate is not necessarily a favorable outcome for a pathogen.

Question 22

You are teaching a class the principles of the Gram stain.Discuss which controls you will use to illustrate what happens during the decolorizing step.

Question 23

Which of the following is the organelle where proteins destined for secretion are separated from other proteins?

A)Plasma membrane
B)Endosome
C)Golgi apparatus
D)Smooth endoplasmic reticulum
E)Rough endoplasmic reticulum

Question 24

Mobile genetic elements that sometimes carry pathogenicity islands are known as

A)Virulence chromosomes
B)Biofilms
C)Plasmids
D)Opportunistic elements
E)Proteasomes

Question 25

Which of the following is not associated with the eukaryotic plasma membrane?

A)Peptidoglycan
B)Proteins
C)Phospholipids
D)Cholesterol
E)Cytoskeletal microfilaments

Question 26

Which of the following is the organelle that is on the path of proteins between the rough endoplasmic reticulum and the Golgi apparatus?

A)Plasma membrane
B)Endosome
C)Golgi apparatus
D)Smooth endoplasmic reticulum
E)Rough endoplasmic reticulum

Question 27

The organelle where secreted proteins are synthesized is

A)Plasma membrane
B)Endosome
C)Golgi apparatus
D)Smooth endoplasmic reticulum
E)Rough endoplasmic reticulum

Question 28

Which of the following are vesicles found in eukaryotic cells?

A)Microtubules
B)Flagella
C)Intermediate filaments
D)Ribosomes
E)Peroxisomes

Question 29

The organelle where lysosome enzymes are packaged is

A)Plasma membrane
B)Endosome
C)Golgi apparatus
D)Smooth endoplasmic reticulum
E)Rough endoplasmic reticulum

Question 30

All of the following can be present in prokaryotic cells except

A)Peptidoglycan
B)Cilia
C)Capsules
D)Pili
E)Plasmids

Question 31

Explain why it is of clinical value to determine whether an infection is caused by a bacterium that possesses a capsule and identify a stain that can be used to confirm the presence of a capsule.

Question 32

Discuss the difference between opportunistic and primary pathogens and the circumstances under which they cause disease.

Question 33

What is a biofilm and why are biofilms clinically problematic? Provide a specific example.

Question 34

Clusters of genes encoding virulence factors are known as

A)Plasmids
B)Pathogenicity islands
C)Quorum clusters
D)Adherence factors
E)Inducing genes

Question 35

Which of the following is a mismatched pair?

A)peroxisomes; fatty acid degradation
B)nucleus; DNA and RNA synthesis
C)Nucleolus; ribosomal RNA synthesis
D)Proteasome; protein synthesis
E)Mitochondria; ATP synthesis

Question 36

Explain why basic dyes and not acidic dyes are used when examining the morphology and arrangement of bacterial cells.

Question 37

Which of the following is the first vesicle for molecules taken up by cells?

A)Plasma membrane
B)Endosome
C)Golgi apparatus
D)Smooth endoplasmic reticulum
E)Rough endoplasmic reticulum

Question 38

When an antibiotic targets a pathogen-specific component,its mechanism of action is

A)Receptor-mediated endocytosis
B)Ubiquitylation
C)Inhibition of a biochemical function that is unique to the pathogen
D)Quorum sensing

Question 39

Secretory vesicles fuse with the

A)Plasma membrane
B)Endosome
C)Golgi apparatus
D)Smooth endoplasmic reticulum
E)Rough endoplasmic reticulum

Question 40

All of the following are present in eukaryotic cells except

A)Lysosomes
B)Endosomes
C)Golgi apparatus
D)Cholesterol
E)Plasma membrane bound oxidative electron transport

Question 41

Describe quorum sensing.Why is it advantageous for a pathogen to use quorum sensing during an infection?

Question 42

Considering the development of high performance high technology methods for detecting and differentiating organisms,justify the continued use of staining techniques.

Question 43

What is the endosymbiont theory? Provide an example of this process.

Question 44

Describe two ways in which pathogens can escape the toxic effects of lysosomes once they have been phagocytosed.

Question 45

Explain why ribosomes are suitable therapeutic targets for some,but not all,infections.

Question 46

Describe the molecular composition and structure of the phospholipid bilayer.Where is the phospholipid bilayer located in prokaryotic and eukaryotic cells?

Question 47

A new device,developed at Lawrence Livermore laboratories,can detect any of 300,000 different pathogens in with one test.Explain the basis for the analysis.

Question 48

Describe three types of endocytosis in eukaryotic cells.

Question 49

Name and describe the three components that contribute to the cytoskeleton in eukaryotic cells.