Microbiology Escelsior Practice Exam

Front 1

Which are the major antigen presenting cells in the primary humoral and cell-mediated immune responses?

Back 1

Macrophages

** They present antigenic components after phagocyotosis of the antigen carrier.

Front 2

Normal bacteria flora help prevent disease by which mechanism?

Back 2

Normal flora

** consumption of nutrients deprive pathogens of these nutrients.

Front 3

Which nonspecific defense helps prevent eye infections?

Back 3

Lysozyme in tears.

** Lysozyme breaks down cell walls.

Front 4

Ciliary escalator is a defense system of which tract?

Back 4

respiratory

Front 5

What is benefit of antiserum therapy?

Back 5

Rapid 100% immunity

Front 6

What is virulence?

Back 6

pathogenicity

Front 7

Majority of food borne infections in US?

Back 7

C. Pylori

Front 8

What type of hyper sensativity could occur in a patient with agammaglobulinemia?

Back 8

type IV cell-mediated reaction

** T-cell mediated reaction

Front 9

In an AIDs test, which substance is used on the ELISA to coat the microtiter wells?

Back 9

HIV antigens

** they are absorbed to the wall

Front 10

What produces antibodies against bacteria, bacterial toxiods, and viruses?

Back 10

B lymphocytes

Front 11

What process kills pathogenic microorganisms in a sample?

Back 11

Pasteurization

Front 12

Commercial sterilization of plastic?

Back 12

Ethylene Oxide

**kills microbes and spores

Front 13

What process is used to sterilize an enzyme solution?

Back 13

Filtration

Front 14

What process uses heat and steam to sterilize? 121 degrees C at 15 psi for 15 minutes?

Back 14

Autoclave

Front 15

How to sterilize an instrument that is sensative to harsh conditions?

Back 15

Chemical growth control

** it kills bacteria on objects without heat.

Front 16

Why is the chemical AZT an effect anti-HIV drug? AZT inhibits ___________?

Back 16

the synthesis of viral DNA

**AZT blocks reverse transcriptase activity?

Front 17

Neissera gonorrhea strains are resistant to penicillin. How is it inactivated by the bacteria?

Back 17

The organism produces enzymes that degrade penicillin when it enters the cell.

Front 18

Which type of chemical agent is used on inanimate objects primarily to reduce the number of pathogen organisms?

Back 18

disinfectant

Front 19

In which phase of microbial growth are prokaryotes the most sensative to antimicrobial agents?

Back 19

log

**In the log phase, prokaryotes are metabollically active and thus most susceptible to antimicrobial agents.

Front 20

A chemical agent widely used to disinfect drinking water and is used on spills involving bodily fluids?

Back 20

halogens

** gas chlorine

Front 21

Germicidal lamp is what type of radiation?

Back 21

nonionizing ultraviolet light

** it's radiation damages DNA through direct contact with microbes.

Front 22

Why is 70% isopropyl alcohol a more effective antimicrobial agent than 100% ethyl alcohol?

Back 22

Denaturation of protein requires water.

Front 23

What chemical property do quaternary amine compounds such as benzalkonium chloride possess that enables them to kill microogranisms?

Back 23

Surfactant ability to dissolve membranes

** Zephiran alters cell permeability, leading to loss of essential cytoplasmic components, especially potassium.

Front 24

How does interferon inactivate a virus after a cell has been infected?

Back 24

interferon inhibits the replication of a virus.

** a viral infected cell is stimulated to produce interferon that binds to a neighboring cell, stimulating it to synethsize antiviral particles.

Front 25

Which process involves reactions that occur in the plasma membrane of a prokaryotic cell?

Back 25

electron transport

** this is the only process that occurs in the plasma membrane

Front 26

Main characteristics of a virus?

Back 26

contains one kind of nucleic acid surrounded by a protein shell.

Front 27

E. coli will have the shortest doubling time in a complex culture medium such as ?

Back 27

glucose

** a complex medium provides nutrients that allow organisms to synthesize all its organic cellular constituents.

Front 28

What specific type of mutation results from a single base pair substitution within a bacterial reading frame causing mRNA codon UAC, to be changed to UAG?

Back 28

nonsense mutation

** it changes a normal codon to a stop codon, UAG stops the synthesis of a protein.

Front 29

What statement best describes gene therapy?

Back 29

the insertion of a missing gene into a defect human cell to combat disease

Front 30

Studies of which subject have been most important in providing relevant information about gene linkage and chromosome mapping?

Back 30

phage transduction

**transduction of bacteriophage is favored because it is simple and facilitates multiple areas of study

Front 31

Bacillus megaterium incubated for five days is more resistant to chemical disinfectants than when grown for a single day. Why?

Back 31

Bacillus megaterium organism forms inert endospores after 5 days.

** inert endospores protect against chemical disinfectants.

Front 32

What allows bactia to live in hypotonic solution without bursting?

Back 32

Cell walls

Front 33

Genomic material of virus particles cannot exist of which form?

Back 33

a virus cannot have different nucleic acids

** not one strand of RNA and one strand of DNA

Front 34

What is the end product of the glycolysis pathway?

Back 34

pyruvic acid

Front 35

What is found in cell walls of gram positive, gram negative, and acid fast microbes?

Back 35

peptidoglycan layers

** peptidoglycan is common to all 3 types

Front 36

Bacteria uses _____ to reproduce?

Back 36

binary fussion

** most bacteria reproduce by splitting into two equal daughter cells through the process of binary fussion.

Front 37

What is the process in which bacteria both generate energy and utilize energy?

Back 37

amphibolism

**amp is the integration of catabolism and anabolism

Front 38

What molecule contains anticodons?

Back 38

tRNA

**tRNA has anticodons to recognize mRNA condons

Front 39

What are some common traits about all fungi?

Back 39

Eukaryote
multicellular
reproduce asexually or sexually
chemoheterotrophic

Front 40

What is the role of plasmids in genetic engineering?

Back 40

R factor plasmids

*** they are used in coloning to ensure that all cut pieces of DNA will have the same sticky ends

Front 41

What is added to a medium to culture bacteria within the clostridium genus?

Back 41

Clostridium is an anaerobe and thioglycolate absorbs Oxygen from the medium

Front 42

How are virus particles commonly quantitated in a bacteriophage suspension?

Back 42

determines the number of plaques formed

** the concentration of a viral suspension is measured by counting the number of plaques formed in agar.

Front 43

What energy producing reaction is pyrovate the primary electron acceptor NADH the primary electron donor and the lactate an end product?

Back 43

fermenatation

** it produces lactate

Front 44

How does oygen effect obligate anaerobes?

Back 44

requires no oxygen and oygen may actually harm them

Front 45

How does oxygen effect aerotolerant anaerobes?

Back 45

requires no oxygen, but its ok if its present.

Front 46

How does oygen effect falcutative anaerobes?

Back 46

requires no oxygen, but if present it may use it

Front 47

What's the difference between aerotolerant anaerobes and facultative anaerobes?

Back 47

Facultative may use oxygen if its present and aerotolerant will NOT.

Front 48

The first synthesis product during replication of a retrovirus?

Back 48

ssDNA

** retroviruses use reverse transcriptase to synthesize a single strand of DNA for replication to double stranded DNA.

Front 49

What would likely happen to an organism if it were exposed to a chemical or physical agent that caused a base deletion in the DNA?

Back 49

A frameshift mutation would occur and the gene would no longer code a functional protein.

** with a frameshift mutation that deletes a codon, the amino acids coded for are altered resulting in production of an inactive protein.

Front 50

Which characteristic accompanies botulism in adults?

Back 50

ingestion of a performed toxin.

** intoxication is produced through ingestion.

Front 51

What chemotherapeutic agent is helpful in alleviating symptoms of genital herpes?

Back 51

Acyclovir Zovirax

** Herpes is a viral disease and acyclovir treats viral infections.

Front 52

Microbial disease accompanied by pseudomembrane covering the tonsils, larynx, and nasal region?

Back 52

Diphtheria

** it produces a pseudomembrane of fibrin, dead tissue, and cells.

Front 53

Which group of virsus cause warts?

Back 53

papovavirus

Front 54

Which information is most useful indistinguishing between food infections and food intoxications?

Back 54

the time symptoms appear

** symptoms of food intoxication occur within a few hours. symptoms of food infection are delayed until the agent can produce enough cells, or invade tissue to produce symptoms.

Front 55

Which viral feature is the primary cause of antigenic shift in the influenza A virus?

Back 55

a segmented RNA genome

Front 56

Which virus is commonly associated with mononucleosis?

Back 56

EB Virus

** epstein barr

Front 57

3 weeks after an episode of pharyngitis antibodies made again the pathogen for the peron's throat infection, cross reacted with the heart tissue and caused cardiac damage...

Which organism was most likely responsible for these events?

Back 57

Streptococcus pyogenes

** S. Pyogenes can cause an immune reaction against the heart valves.

Front 58

What is unique of a gram positive?

Back 58

it takes stain, they typically lack the outter membrane found in gram negative

Front 59

What is the function of reverse transcriptase in HIV?

Back 59

to convert the genetic information on viral RNA into DNA

Front 60

What is malaria?

Back 60

Eukaryotic protist

** produces fever and headache

*** also a plasmodium

Front 61

Staphylococcus Aureus

Back 61

colonization of human skin and upper respiratory tract begins 24 hour after birth

** 20% of all human are long term carriers

** signs: pimples, boils, cellulitis

Front 62

Trichomoniasis

Back 62

Protozoan infection

Front 63

Gonorrhea

Back 63

bacterial infection

Front 64

Patient shows signs of irratation of vaginal wall and a thick abnormal discharge.

Analysis of discharge shows an abundance of budding single cell fungi.

Antimycotic vaginal cream is given..

*** WHAT IS THE CAUSATIVE AGENT?

Back 64

Vaginal Candidiasis

*** Candidiasis is a fungal infection

Front 65

In what sense is fever a defensive response to disease?

Back 65

high temperature enhances the effectiveness of interferons.

Front 66

What kind of pathogens are resident or transient species of pathogenic microbes that cause disease under unusual conditions?

Back 66

opportunistic

** a generally harmless organism can become pathogenic in a host who is debilitated, traumatized, on antibiotics, or immunocompromised.

Front 67

What type of hepatits is transmitted by the fecal oral route?

Back 67

hep A

(ass to mouth)

Front 68

VD with generalized skin rash?

Back 68

secondary syphilis

Front 69

STD involves intracellular parasite of epithelial cells of the urogential tract?

Back 69

Chlamydia Trachomatis

**this is a parasite that reproduces only with the host cells

Front 70

What's the difference in pneumonic plague and bubonic plague?

Back 70

Pneumonic is respiratory

Bubonic is lymphatic

Front 71

hep B virus

Back 71

serum hepatitis

retrovirus

replication takes place in the liver

Front 72

Why was urgency placed on the development of hep b vaccine?

Back 72

there is a strong correlation between live cancer and chronic hep B infections.

Front 73

Whats a retro virus?

Back 73

reverse transcriptase

produces DNA from its RNA

RNA -> DNA -> RNA -> Protein

Front 74

Bacterial tetanus

Back 74

preventable with injection of a toxoid

Front 75

cryptosporidiosis

Back 75

parasitic disease that is VERY opportunistic

fecal-oral route

diarrhea

infects the small intestine on its exit

Front 76

patient has cronic cough, low grade fever malaise, sputum reveals slender acid fast rods...
This reveals which disease?

Back 76

TB

tuberculosis

** acid fast rods

Front 77

Which action represents a relationship among microbes called mutualism?

Back 77

the nitrogen fixing symbiotic relationship between a species of bacteria and leguminous plants

** mutualism where two organisms live together for mutual benefit

Front 78

Scanning electron microscope uses ____?

Back 78

Electron beams

Front 79

Fluorescence microscope examines ____?_____

Back 79

intact organisms

Front 80

Extremely thin slices and coated with metals for which microscope?

Back 80

transmission electron

Front 81

_______% gelatin is thick enough to creat a solid surface for growth

Back 81

12%

Front 82

_______ acid bacteria are grown anaerobically to ripen swiss and cheddar cheese

Back 82

lactic

Front 83

What term defines the process which bacteria use nitrogen gas to form ammonia?

Back 83

nitrogen fixation

Front 84

______ inhabit the intestines and are present in feces

Back 84

fecal coliforms

Front 85

Which structures contain the nitrogenase produced by symbiotic relatioship between rhizobium and legumes?

Back 85

bacteriods

** bacteria change into bacteriods in the root cells causing the root cells to enlarge

Front 86

Which organisms essential in the sulfur cycle use sulfate as an electron accepor in anaerobic respiration?

Back 86

sulfate reducing bacteria

** they use sulfates as electron acceptors

Front 87

what antibacterial compound did Ehrlich use to treat syphilis?

Back 87

Salvarsan