Test 4 Questions

Question 1

Describe how the tetanus toxin produces deadly symptoms in humans. Be sure to include cell types, proteins, and processes involved.

Answer 1

The toxin binds to inhibitory neurons and blocks release of Glycine. The neurons constantly release acetylcholine, causing constant muscle contractions, eventually preventing breathing.

Question 2

Describe the steps that must happen for a vaccines to produce life-long immunity to a pathogen. Be sure to include types, proteins, and processes involved.

Answer 2

A B cell must recognize an antigen on the vaccine. The B cell must interact with a TH2 cell that also recognizes the antigen. The B cell must produce effective antibodies against the antigen. The B cell must produce Memory cells.

Question 3

A large number of new infections of a particular disease in one country within a limited time period is called a:

Answer 3

Epidemic

Question 4

A major factor in the ability of Streptococcus species to cause disease is the ability to produce a:

Answer 4

capsule

Question 5

A toxin that works only in the intestinal tract is called a:

Answer 5

Enterotoxin

Question 6

A zoonosis is a disease that humans often acquire from a:

Answer 6

animal

Question 7

The most abundant bacterial genus in the human skin microflora is:

Answer 7

Staphylococcus

Question 8

The fact that the immune system does not recognize self-antigens is referred to as:

Answer 8

tolerance

Question 9

The LD50 is the measure of the number of pathogen cells required to cause ___ in 50% of infected hosts

Answer 9

death

Question 10

The cells that produce all of the circulating antibodies are____cells

Answer 10

plasma

Question 11

Streptococcus species are common abundant members of the human microbiome in what part of the body?

Answer 11

Upper respiratory tract

Question 12

A live non-virulent strain that serves as a vaccine is called a _____ strain.

Answer 12

attenuated

Question 13

When phagocytes try to kill bacteria using oxygen radicals, it is referred to as a ____ burst

Answer 13

respiratory

Question 14

A nonliving item that transmits a pathogen to a new host is called a:

Answer 14

fomite

Question 15

The set of proteins that bind to antibody-tagged bacteria and cause lysis are called:

Answer 15

complement

Question 16

The major antibody class produces during a primary immune response is:

Answer 16

IgM

Question 17

TH2 cells recognize antigens presented by ___ cells

Answer 17

B

Question 18

Cytokines are…
1)Proteins that insert in bacterial membranes leading to cell death
2)Antibodies that recognize virus-infected cells
3)Proteins that allow immune cells to recognize foreign antigens
4)Proteins that slow the growth of tumor cells
5)Proteins that stimulate the activity of immune cells

Answer 18

Proteins that stimulate the activity of immune cells

Question 19

How does sugar aid in the process of tooth cavity development?
1)The sucrose can be broken down by fermentation
2)Creation of acid byproducts promotes enamel decay
3)Sucrose is used to produce a polysaccharide that allows for bacterial adherence to tooth surfaces
4)All of the above
5)None of the above

Answer 19

All of the above

Question 20

In epidemiology, the value R0 refers to:
1)The average number of pathogen cells that must enter an host to cause an infection
2)The first person that exhibits an infection during an outbreak
3)The time period when no new infections are detected
4)The average number of additional individuals that will be infected by one infected host

Answer 20

The average number of additional individuals that will be infected by one infected host

Question 21

An AB-form toxin is a toxin in which:
1)A single toxin protein must be cleaved into two parts in order to function
2)two proteins must be produced, one by the pathogen and one by the host, in order to have full effect
3)Two proteins act together, one binding the host cell and the other entering the cell
4)A toxin has different effects on two different host cell types

Answer 21

Two proteins act together, one binding the host cell and the other entering the cell

Question 22

Which of the following are lymphocytes?
1)only B cells
2)only T cells
3)phagocytic cells
4)B and T cells
5)Phagocytic cells, B cells, and T cells

Answer 22

B and T cells

Question 23

Macrophages are:
1)derived from bone marrow stem cells
2)part of the INNATE immune response
3)capable of presenting an antigen to a T cell
4)able to capture and destroy many pathogens they encounter
5)All of the above are TRUE statements

Answer 23

All of the above are TRUE statements

Question 24

Memory cells allow rapid response to an antigen because:
1)They are present in high numbers
2)They do not require T cells for activation
3)They divide more rapidly than other cells
4)They are already filled with antibody molecules

Answer 24

They do not require T cells for activation

Question 25

How is a macrophage protected from the oxygen and nitrogen radicals used for the destruction of pathogens? 1)The destruction takes place within a membrane-bound compartment 2)The macrophage contains many oxidases and nitrogenases that break down the radicals 3)Extra appendages separate the radicals from important organelles 4)The macrophage has a mucus barrier to keep pathogens away from its surface

Answer 25

The destruction takes place within a membrane-bound compartment

Question 26

A disease that is "Endemic" is: 1)Spreading rapidly through a local population 2)Spreading rapidly through a very large area 3)Unable to be reduced by vaccination 4)caused by an unidentified pathogen 5)Constantly present at a low level within a population

Answer 26

Constantly present at a low level within a population

Question 27

Which of the following factors alter vaginal microflora? 1)Fertility 2)Age 3)Hormone levels 4)pH 5)All of the above

Answer 27

All of the above

Question 28

An example of a pattern recognition receptor (PRR) is: 1)Toll like receptors 2)B cell receptor 3)T cell receptor 4)Antibody

Answer 28

Toll like receptors

Question 29

A disease that exhibits a high incidence in the USA during late summer and fall, and essentially no incidence during the winter, is indicative of: 1)A mosquito-borne disease 2)A direct host to host transferred disease 3)A disease transmitted by tree pollen 4)A disease transmitted in ground beef

Answer 29

A mosquito-borne disease

Question 30

Which region of the human body is normally virtually devoid of bacteria? 1)Upper respiratory tract 2)Lower respiratory tract 3)Gastrointestinal tract 4)Sinuses 5)Hair follicles

Answer 30

Lower respiratory tract

Question 31

Which of the following toxin names refers to the LPS in the Gram-negative outer membrane? 1)Exotoxin 2)α -toxin 3)Endotoxin 4)Protein toxin 5)Enterotoxin

Answer 31

Endotoxin

Question 32

Which of the following is a likely cause of a Common Source Epidemic? 1)A mosquito transferring malaria to several individuals 2)A student with a cold sneezing on three professors 3)Contamination of food with Norovirus by an infected chef 4)An intravenous drug user with HIV passing a contaminated needle to another user

Answer 32

Contamination of food with Norovirus by an infected chef

Question 33

Adherence to host cells can be increased by each of the following EXCEPT: 1)Surface proteins 2)Fimbriae 3)Pili 4)Capsules 5)Flagella

Answer 33

Flagella

Question 34

A role of T cytotoxic cells in the immune response it to... 1)engulf pathogens 2)produce antibodies 3)directly kill pathogens 4)kill cells that are infected by a pathogen 5)increase the activity of macrophages

Answer 34

kill cells that are infected by a pathogen

Question 35

The genus Bacteroids is very important in the human gut microflora because: 1)It frequently causes colitis 2) It breaks down complex polysaccharides 3)It produces many vitamins 4)It solubilizes fats 5)It spreads many antibiotic resistance genes

Answer 35

It breaks down complex polysaccharides

Question 36

Which of the following types of proteins is not likely to be considered a virulence factor? 1)An exotoxin 2)A pilus subunit 3)A DNA Polymerase 4)A chelator 5)A fimbriae subunit

Answer 36

A DNA Polymerase

Question 36

In the field of epidemiology, the term "reservoir" refers to: 1)A location where a pathogen can be maintained in order to allow future infection of a population 2)A stock of vaccine maintained to combat a disease outbreak 3)A stock of antibiotic maintained to combat a disease outbreak 4)A stock of pathogen stored in a safe place for future research

Answer 36

A location where a pathogen can be maintained in order to allow future infection of a population

Question 37

VDJ recombination is required for: 1)Production of various types of phagocytes 2)Production of antibody diversity 3)Elimination of self reactive antibodies 4)Acquisition of antibiotic resistance

Answer 37

Production of antibody diversity

Question 38

Gastric cancer can result from the prolonged infection by what genus of bacteria? 1)Bacteroids 2)Helicobacter 3)Escherichia 4)Clostridium 5)Methanobrevibacteria

Answer 38

Helicobacter

Question 39

Class II Major Histocompatibility Complexes function as antigen-presenting molecules on: 1)The surface of all nucleated cells in the entire body 2)Macrophages, dendritic cells, and B lymphocytes 3)Red blood cells 4) 1 and 2

Answer 39

Macrophages, dendritic cells, and B lymphocytes

Question 40

The toxin produces by clostridium botulinum causes what symptoms in humans? 1)Constant muscle contraction 2)Constant muscle relaxation 3)Diarrhea 4)Muscle cell lysis 5)Blood cell lysis

Answer 40

Constant muscle relaxation

Question 41

Second exposure to antigens primarily triggers the production of: 1)IgA 2)IgD 3)IgE 4)IgG

Answer 41

IgG

Question 42

What type of nutrient is frequently a limiting factor in the growth of microorganisms within a host? 1)Iron 2)Lipids 3)Magnesium 4)Proteins 5)Sugars

Answer 42

Iron

Question 43

A host to host epidemic generally exhibits what pattern of incidence in a population? 1)A rapid increase followed by a rapid decline 2)A rapid increase followed by a very slow decline 3)A slow increase followed by a rapid decline 4)A slow increase followed by a slow decline

Answer 43

A slow increase followed by a slow decline

Question 44

Which of the following does NOT increase the ability of phagocytes to engulf bacteria? 1)Lipopolysaccharide on the bacterial surface 2)Cytokine activation by T-cells 3)Capsule on the bacterial surface 4)Peptidoglycan on the bacterial surface 5)Opsonization of the bacterial surface

Answer 44

Capsule on the bacterial surface

Question 45

As you move from the stomach further down the gastrointestinal tract, how do pH and oxygen availability change? 1)pH and oxygen availability increase 2)pH and oxygen availability decrease 3)pH increases and oxygen availability decreases 4)pH decreases and oxygen availability increases 5)pH and oxygen availability remain constant throughout

Answer 45

pH increases and oxygen availability decreases

Question 46

The term "Opsonization" refers to: 1)Specific interaction between a normal microbial flora species and a host cell surface 2)Attachment of a viral particle to a host cell surface 3)Removal of the viral capsid from the nucleic acid following cell entry 4)Binding of an antibody to a pathogen leading to increased phagocytosis 5)Recognition of a pathogen PAMP by a phagocyte

Answer 46

Binding of an antibody to a pathogen leading to increased phagocytosis