final lab exam

Question 1

Is the disk diffusion method measuring bacteriostatic or bactericidal effects?

Answer 1

It cannot distinguish between bacteriostatic or bactericidal effects

Question 2

In which growth phase is an organism most susceptible to an antimicrobial agent?

Answer 2

the exponential or log phase

Question 3

Diseases that are referred to as EIDs have only been discovered in the past fifty years. T/F

Answer 3

False

Question 4

A host is not considered diseased until an infection changes one’s state of health. T/F

Answer 4

True

Question 5

Reservoirs of infections are always living organisms. T/F

Answer 5

False

Question 6

Biofilms provide pathogens with an adhesion mechanism and aid in resistance to antimicrobial agents. T/F

Answer 6

True

Question 7

In A-B exotoxins, the B component…

a) is the receptor on the host membrane to which A binds
b) is the toxin
c) binds the receptor so the toxin can enter the cell
d) inactivate the toxin

Answer 7

C. binds to the receptor so the toxin can enter the cell

Question 8

Which of the following statements is TRUE?

Both members are harmed in a symbiotic relationship.
A parasite is not in symbiosis with its host.
Members of a symbiotic relationship cannot live without each other.
At least one member must benefit in a symbiotic relationship.
Symbiosis always refers to different organisms living together and benefiting from each other.

Answer 8

At least one member must benefit in a symbiotic relationship

Question 9

The major significance of Robert Koch’s work is that

Microorganisms can be cultured.
Microorganisms cause disease.
Diseases can be transmitted from one animal to another.
Microorganisms are the result of disease.
Microorganisms are present in a diseased animal.

Answer 9

Microorganisms cause disease

Question 10

Symptoms of disease differ from signs of disease in that symptoms

Are changes felt by the patient.
Are specific for a particular disease.
Are changes observed by the physician.
None of the answers is correct.
Always occur as part of a syndrome.

Answer 10

Are changes. felt by the patient

Question 11

Focal infections initially start out as

  Systemic infections. 
  Local infections. 
  Sepsis. 
  Septicemia. 
  Bacteremia.

Answer 11

Local infections

Question 12

The science that deals with when diseases occur and how they are transmitted is called

  Communicable disease. 
  Public health. 
  Epidemiology. 
  Ecology. 
  Morbidity and mortality.

Answer 12

Epidemiology

Question 13

The ability of some microbes, such as Trypanosoma
or Giardia to alter their surface molecules and evade destruction by the host’s antibodies is called
Antigenic variation.
Cytopathic effect.
Virulence.
Lysogenic conversion.
Cytocidal effect.

Answer 13

Antigenic variation

Question 14

The ID50 is
The dose that will cause an infection in 50 percent of the test population.
The dose that will cause an infection in some of the test population.
The dose that will kill 50 percent of the test population.
The dose that will kill some of the test population.
A measure of morbidity.

Answer 14

The dose that will cause infection in 50 percent of the test population

Question 15

Cytopathic effects are changes in host cells due to
  Viral infections. 
  Fungal infections. 
  Helminthic infections. 
  Bacterial infections. 
  Protozoan infections.

Answer 15

Viral infections

Question 16

Which of the following is an example of a fomite?
  a mosqito 
  an used hypodermic needle 
  an asymptomatic person 
  a toxin. 
  superantigens

Answer 16

A used hypodermic needle

Question 17

All of the following are used by bacteria to attach to host cells EXCEPT
  Capsules. 
  A-B toxins. 
  Fimbriae. 
  Ligands. 
  M protein.

Answer 17

A-B toxins

Question 18

The epidermis is composed of connective tissue and provides protection from the external environment. T/F

Answer 18

False

Question 19

Maturation of stem cells into mature B lymphocytes occurs in the red bone marrow.

True
False

Answer 19

True

Question 20

The inflammatory response can only be triggered by an infection.

True
False

Answer 20

False

Question 21

Apoptosis happens when there is significant leakage of cellular contents out of the cell.

True
False

Answer 21

False

Question 22

An example of a TLR would be peptidoglycan found in the cell wall of gram-positive bacteria. T/F

Answer 22

False

Question 23

All of the following protect the skin and mucous membranes from infection EXCEPT

  The "ciliary escalator."
  Multiple layers of cells. 
  Tears. 
  Saliva. 
  Interferons

Answer 23

interferons

Question 24

A differential cell count is used to determine each of the following EXCEPT

The total number of white blood cells.
The numbers of each type of white blood cell.
The number of red blood cells.
Leukocytosis.
Leukopenia.

Answer 24

The number of red blood cells

Question 25

The complement protein cascade is the same for the classical pathway, alternative pathway, and lectin pathway beginning with the activation of ``` C1. C3. C6. C2. C5. ```

Answer 25

C3

Question 26

Margination refers to The chemotactic response of phagocytes. Dilation of blood vessels. Adherence of phagocytes to the lining of blood vessels. The adherence of phagocytes to microorganisms. The movement of phagocytes through walls of blood vessels.

Answer 26

Adherence of phagocytes to the lining of blood vessels

Question 27

``` Plasma cells are activated by a(n) T cell. APC. Antigen. B cell. Memory cell. ```

Answer 27

Antigen

Question 28

What type of immunity results from recovery from mumps? naturally acquired active immunity naturally acquired passive immunity artificially acquired passive immunity artificially acquired active immunity innate immunity

Answer 28

Naturally acquired active immunity

Question 29

``` The antibodies found in mucus, saliva, and tears are IgD. IgA. IgM. IgE. IgG. ```

Answer 29

IgA

Question 30

``` Each of the following provides protection from phagocyte digestion EXCEPT M protein Leukocidins Biofilms Capsules IgM. ```

Answer 30

IgM

Question 31

Toxoid vaccines, such as the vaccines against diphtheria and tetanus, elicit a(n) antibody response against gram-positive bacteria. immune complex. antibody response against these bacterial toxins. TC cell response. dendritic cell proliferation.

Answer 31

Antibody response against these bacterial toxins

Question 32

In a direct ELISA, the test detects the presence of________________. ``` complement agglutination substrate antigen antibodies ```

Answer 32

Antigen

Question 33

A hybridoma results from the fusion of a(an) ``` B cell with a myeloma cell. B cell with a T cell. antigen with an antibody. myeloma cell with a virus. antigen with a B cell. ```

Answer 33

B cell with a myeloma cell

Question 34

Monoclonal antibodies are used in diagnostic tests and disease treatments because they are highly specific, they can be produced in large quantities, and they contain a mixture of antibodies. are highly specific and they can be produced in large quantities. can be produced in large quantities. are highly specific. contain a mixture of antibodies.

Answer 34

Are highly specific and they can be produced in large quantities

Question 35

In a viral hemagglutination inhibition test, if the patients have no antibodies for a virus in the serum, the red blood cells will ________________________in the presence of the virus. ``` be in solution lyse agglutinate fluoresce precipitate ```

Answer 35

Agglutinate

Question 36

Live weakened polio virus can be used directly in a(n) ``` subunit vaccine. conjugated vaccine. attenuated whole-agent vaccine. toxoid vaccine. inactivated whole-agent vaccine. ```

Answer 36

Attenuated whole-agent vaccine

Question 37

In a complement fixation test, a patient's serum, is mixed with Mycobacterium and guinea pig complement. Then, after some time of incubation, sheep red blood cells, and anti-sheep red blood cell antibodies are mixed in a test tube. What happens if the patient has antibodies to Mycobacterium? ``` Hemagglutination occurs. Bacteria fluoresce. Hemolysis occurs. Hemagglutination-inhibition occurs. No hemolysis occurs. ```

Answer 37

No hemolysis occurs

Question 38

Palivizumab is used to treat respiratory syncytial virus disease. This antiviral drug is a(n) ``` nucleoside analog. immunosuppressive. vaccine. toxoid. monoclonal antibody. ```

Answer 38

monoclonal antibody

Question 39

Most of the available antimicrobial agents are effective against ``` All of the answers are correct. bacteria. viruses. fungi. protozoa. ```

Answer 39

bacteria

Question 40

Niclosamide affects ONLY mitochondria. You would expect this drug to be effective against ``` viruses. Mycobacterium tuberculosis. gram-negative bacteria. helminths (parasitic worms) gram-positive bacteria. ```

Answer 40

helminths (parasitic worms)

Question 41

In the presence of penicillin, a cell dies because the cell walls gets digested by the drug the osmotic pressure lyses the dividing wall-less cells it lacks a cell membrane. its growth its halted its contents leak out.

Answer 41

The osmotic pressure lyses the dividing wall-less cells

Question 42

Which of the following would be selective against the tuberculosis? streptogramin- inhibits protein synthesis ethambutol- inhibits mycolic acid synthesis vancomycin- inhibits peptidoglycan synthesis bacitracin- inhibits peptidoglycan synthesis streptomycin- inhibits protein synthesis

Answer 42

Ethambutol-inhibits mycelia acid synthesis

Question 43

``` Bacterial cells have ______________ ribosomes. 50S none, they are procaryotes 80S 30S 70S ```

Answer 43

70s

Question 44

Which of the following statements about drug resistance is FALSE? It may be due to misuse of a drug. It is found only in gram-negative bacteria. It may be carried on a plasmid. It may be due to enzymes that degrade some antibiotics. It may be transferred from one bacterium to another during conjugation.

Answer 44

It is found only in gram-negative bacteria

Question 45

``` Which one of the following does NOT belong with the others? cephalosporin monobactam penicillin tetracycline ampicillin ```

Answer 45

tetracycline