Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

SAC Microbiology > Lecture 13 > Flashcards

Lecture 13 Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

A genomic island that increases the “fitness” of a microorganism is called a(n) ____.

A) plasmid gene
B) pathogenicity island
C) phage gene
D) secretion system

A

B) pathogenicity island

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

____ move whole blocks of DNA from one organism to another.

A

Horizontal gene transfers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

If the genomic island increases the “fitness” of a microorganism during interaction with a host, it is called a ____.

A

pathogenicity island

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which of the following is NOT a feature of a pathogenicity island?

A) They can be acquired through horizontal gene transmission.
B) They don’t confer fitness to the pathogen.
C) They are flanked by plasmid or phage sequences.
D) The ratio of GC/AT is different in the islands vs. the genome.

A

B) They don’t confer fitness to the pathogen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Pathogenecity islands are acquired through ____.

A

horizontal gene transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Because the pathogenecity island is different, the ___ sequence is different from the genome.

A

GC/AT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The pathogenicity island is flanked by ____.

A

plasmid or phage sequences

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

All of the following are used for microbial attachment EXCEPT _____.

A) capsids
B) pili
C) fimbriae
D) ribosomes

A

D) ribosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Examples of microbial attachments

A

Capsids, envelopes, pili, and fimbriae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Exotoxins target all of the following EXCEPT _____.

A) vesicular trafficking
B) cytoskeleton alteration
C) protein synthesis
D) DNA synthesis

A

D) DNA synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

8 categories of microbial exotoxins

A

plasma membrane disruption,
cytoskeleton alterations
protein synthesis disruption
cell cycle disruption
signal transduction disruption
cell-cell adhesion disruption
vesicular trafficking
exocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

All of the following are methods intracellular pathogens can use to survive inside a host cell EXCEPT _____.

A) create a capsule.
B) escape the phagosome.
C) survive in the phagolysosome.
D) prevent phagosome-lysosome fusion

A

A) create a capsule.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Once inside the phagosome, intracellular pathogens have three options to avoid being killed by the phagolysosome:

A

survive in a phagolysosome
prevent phagosome-lysosome fusion
escape the phagosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Protozoan antigenic variation causes the host’s immune system to continually make______.

A) macrophages
B) T-cells
C) NK cells
D) antibodies

A

D) antibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Switching to a new VSG (antigenic variation) allows the pathogen to avoid the ____ and is allowed to produce more ____.

A

antibody response; organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Small genetic changes to a virus that result in viruses with similar antigenic properties is called _____.

A) antigenic drift
B) antigenic shift
C) toxin production
D) antigenic variation

A

A) antigenic drift

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

All of the following are methods protozoans use to avoid the host immune response EXCEPT ____.

A) antigenic masking
B) toxin production
C) antigenic variation
D) immunosuppression

A

B) toxin production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Protozoans lack potent ___.

A

toxins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Protozoan immune-avoidance strategies include (4):

A

antigenic masking
antigenic variation
intracellular location
immunosuppression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Genomic island

A

a horizontally acquired region of the bacterial chromosome that has an altered GC content and segments of phages or plasmid DNA that mark it as different from the rest of the genome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Pathogenicity island

A

a genomic island that contains virulence factors that increase the fitness of the organism in the host

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Capsule

A

coat bacterial cell walls and can prevent phagocytes from binding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Cell-surface proteins are components of the cell wall that ____.

A

prevent detection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Quorum sensing

A

used to communicate with other pathogens about population size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Antigenic variation

A

100 known serotypes of rhinovirus; each virus has a unique capsid protein. Antibodies to one capsid protein are not effective on another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Antigenic shift

A

Two strains of influenza virus infect the same cell and the genomes get mixed. This makes a dramatically different virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Antigenic drift

A

Random mutations can occur within the cell that a virus infects creating small changes in virus proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Antigenic Masking

A

Some protozoans coat themselves in host antigens to avoid detection by the immune system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Antigenic Variation

A

Just like viruses and bacteria, some protozoans can alter their surface antigens to prevent antibody binding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Intracellular Location

A

Just like some bacteria, protozoans have found ways to live inside the host cell to prevent detection

31
Q

Immunosuppression

A

Some protozoans induce the secretion of anti-inflammatory cytokines to reduce the innate immune response

32
Q

____ contribute to a pathogen’s ability to cause disease.

A

Virulence factors

33
Q

____ and ____ allow pathogens to invade host tissue and cause tissue damage

A

Exoenzymes; toxins

34
Q

____ is the lipid A component of the LPS of the gram-negative cell envelope.

A

Endotoxin

35
Q

____ are proteins secreted mainly by gram-positive bacteria, but also are secreted by gram-negative bacteria

A

Exotoxins

36
Q

Bacterial pathogens may evade the host immune response by producing ____ to avoid phagocytosis.

A

capsules

37
Q

Viral pathogens use ____ for initiating infections and antigenic variation to avoid immune defenses.

A

adhesins

38
Q

Influenza viruses use both ____ and ____ to avoid being recognized by the immune system.

A

antigenic drift; antigenic shift

39
Q

Fungal and parasitic pathogens use pathogenic mechanisms and virulence factors that are similar to those of ____ pathogens.

A

bacterial

40
Q

____ initiate infections through the interaction of adhesins with receptors on host cells.

A

Fungi

41
Q

____ are able to avoid the immune system by coating their exteriors with glycan molecules that make them look like host cells or by suppressing the immune system.

A

Helminthic worms

42
Q

Which of the following is a major virulence factor for the fungal pathogen Cryptococcus?

A) hemolysin
B) capsule
C) collagenase
D) fimbriae

A

B) capsule

43
Q

Phospholipases are enzymes that do which of the following?

A) degrade antibodies
B) promote pathogen spread through connective tissue.
C) degrade nucleic acid to promote spread of pathogen
D) degrade cell membranes to allow pathogens to escape phagosomes

A

D) degrade cell membranes to allow pathogens to escape phagosomes

44
Q

Which of the following applies to hyaluronidase?

A) It acts as a spreading factor.
B) It promotes blood clotting.
C) It is an example of an adhesin.
D) It is produced by immune cells to target pathogens.

A

A) It acts as a spreading factor.

45
Q

You have recently identified a new toxin. It is produced by a gram-negative bacterium. It is composed mostly of protein, has high toxicity, and is not heat stable. You also discover that it targets liver cells. Based on these characteristics, how would you classify this toxin?

A) superantigen
B) endotoxin
C) exotoxin
D) leukocidin

A

C) exotoxin

46
Q

Which of the following would be a virulence factor of a pathogen?

A) a surface protein allowing the pathogen to bind to host cells
B) a secondary host the pathogen can infect
C) a surface protein the host immune system recognizes
D) the ability to form a provirus

A

A) a surface protein allowing the pathogen to bind to host cells

47
Q

Which of the following choices lists the steps of pathogenesis in the correct order?

A) invasion, infection, adhesion, exposure
B) adhesion, exposure, infection, invasion
C) exposure, adhesion, invasion, infection
D) disease, infection, exposure, invasion

A

C) exposure, adhesion, invasion, infection

48
Q

Antigenic _____ is the result of re-assortment of genes responsible for the production of influenza virus spike proteins between different virus particles while in the same host, whereas antigenic _____ is the result of point mutations in the spike proteins.

A

shift; drift

49
Q

Adhesins are usually located on _____ of the pathogen and are composed mainly of _____ and _____.

A

surface; proteins; sugars

50
Q

The glycoprotein adhesion gp120 on HIV must interact with ______ on some immune cells as the first step in the process of infecting the cell.

A

CD4

51
Q

Cilia, fimbriae, and pili are all examples of structures used by microbes for _____.

A

adhesion

52
Q

A(n) ______ pathogen causes disease only when conditions are favorable for the microorganism because of transfer to an inappropriate body site or weakened immunity in an individual.

A

opportunistic

53
Q

Viruses are generally ultramicroscopic, typically from __ nm to __ nm in length. Some large viruses have been found.

A

20; 900

54
Q

____ are acellular and consist of a nucleic acid, DNA or RNA, but not both, surrounded by a protein ____.

A

Virions; capsid

55
Q

____ are obligate intracellular parasites

A

Viruses

56
Q

Viruses typically have limited ____ and infect specific cell types.

A

host ranges

57
Q

The component(s) of a virus that is/are extended from the envelope for attachment is/are the:

A) capsomeres
B) spikes
C) nucleic acid
D) viral whiskers

A

B) spikes

58
Q

Which of the following does a virus lack? Select all that apply.

A) ribosomes
B) metabolic processes
C) nucleic acid
D) glycoprotein

A

A) ribosomes
B) metabolic processes

59
Q

The envelope of a virus is derived from the host’s:

A) nucleic acids
B) membrane structures
C) cytoplasm
D) genome

A

B) membrane structures

60
Q

What is another name for a nonenveloped virus?

A) enveloped virus
B) provirus
C) naked virus
D) latent virus

A

C) naked virus

61
Q

Which of the following leads to the destruction of the host cells?

A) lysogenic cycle
B) lytic cycle
C) prophage
D) temperate phage

A

B) lytic cycle

62
Q

A virus obtains its envelope during which of the following phases?

A) attachment
B) penetration
C) assembly
D) release

A

D) release

63
Q

Steps of pathogenesis

A

Entry
Tissue attachment and colonization
Immune avoidance
Host damage
Pathogen exit

64
Q

Genomic island

A

a horizontally acquired region of the bacterial chromosome that has an altered GC content and segments of phages or plasmid DNA that mark it as different from the rest of the genome

65
Q

Pathogenicity island

A

a genomic island that contains virulence factors that increase the fitness of the organism in the host.

66
Q

Adhesin

A

any microbial factor that promotes attachment

67
Q

3 features of pathogenicity islands:

A

1) G/C content is different than the rest of the chromosome.
2) Islands are flanked by phage or plasmid genes.
3) Increase the fitness of the organism

68
Q

3 types of EXOtoxins:

A

1) Two-Subunit AB
2) Membrane disrupting
3) Superantigens

69
Q

The General Secretion Pathway secretes ____.

A

virulence factors

70
Q

Type II secretion uses:

A

Pili to force protein through an outer pore.

71
Q

Type III secretion is like a ____.

A

syringe

72
Q

3 methods of intracellular escape:

A

1) Survive in phagolysosome
2) Prevent phagosome-lysosome fusion
3) Escape from phagosome

73
Q

3 methods of extracellular immune avoidance:

A

1) Capsules
2) Antigenic variation
3) Quorum sensing

SAC Microbiology (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions