Microbiology test questions
third section (micrl)
1. 0.1 ml. are transferred from a suspension containing 10 ml. of
E. coli at
9
10 (ten to the ninth power) bacteria
per ml. into 0.9 ml. sterile medium. The second culture
contains________ bacteria per ml. a.one million b.ten million c.100 million
d.one billion e.none of these
C
2. Based on a counting chamber estimate, you dilute a culture so
as to deposit 200 bacteria onto a spread plate, but in the morning, you only
count 50 colonies, the % viability is a.100 b.50 c.10 d.5 e.none of these
e
3. You count 100 bacteria in 10 squares of a counting chamber.
Your total bacterial count is _______ per
ml. a.20 million b.200 million c.2 billion d.20 billion e.none of these
b
4. The first edition of Bergey’s Manual was published in about
a.1800 b.1850 c.1900 d.1920 e.1950
d
5. Another name for cyanobacteria is a.myxobacteria
b.sphaerotilus c.cyanophyta d.blue—green algae e.more than one of these
e
6. To transfer 0.2 ml. of liquid, a ___ml. pipet should be used.
a.0.1 twice b.0.5 c.1.0 d.2.0 e.more than one of these would be equally useful
b
7. A _____ml. pipet would be more accurate for transferring 5.0
ml. of liquid. a.5.0 measuring b.5.0 serological
a
8. 0.2 ml. is spread onto a plate and gives rise to 100 colonies.
The viable count per ml. of this suspension is a.100 b200 c.300 d.400 e.none of
these
e
9. Which was thought to be critical for the initial generation of
Earth’s oxidizing atmosphere? a.bacterial photosynthesis b.anoxygenic
photosynthesis c.cyanobacteria d.green plants e.none of these
C
10. Which is probably involved in nitrogen fixation? a.trichome
b.hormogonia c.heterocyst d.akinete e.none of these
C
11. ________
can fix molecular
nitrogen. a.cyanobacteria b.Rhizobium c.Azotobacter d.two of these e.all of
these
e
12. Salmonella only causes intestinal infections. a.true b.false
b
13. E. coli is the primary inhabitant of the human large intestine.
a.true b.false
b
14. Rickettsias a.fix nitrogen b.cause syphilis c.have leaky membranes
d.move by “gliding” e.none of these
C
15. __________
don’t have cell
walls. a.spirochetes b.vibrios c.Pseudomonads d.mycoplasmas e.none of these
d
16. “Pyogenic” means a.fever-provoking b.pus-causing c.non—motile
d.photosynthetic e.more than one of these
b
17. ________
are acid-fast. a.E.
coli b.Mycobacteria c.cyanobacteria d.Staphylococci e.all of these
b
18. Tuberculosis, because of antibiotics, is currently almost
non-existent on this planet. a.true b.false
b
19. All purple bacteria are purple. a.true b.false
b
20. Chemolithotrophs have a major significance in that they cause
numerous diseases. a.true b.false
b
21. Give causative agents for:
Leptospiros is
Leprosy
Legionnaire’s disease
Impetigo
Histoplasmosis
Leptospira sp. ;M. leprae;L.pneumophila;S . aureus&S . pyogenes micrL3 Q# 21 E
22. The _______
is responsible for
specific adsorption of a bacteriophage to a bacterium. a.capsid b.pins c.contractile
sheath d.base plate e.none of these
e
23. A (n) -containing
virus would be more likely to contain reverse
transcriptase. a.capsid b.DNA c.RNA d.protein e.none of
these would be more likely than another
C
24. Restriction endonucleases are produced by a.bacteria b.viruses
c.both bacteria and viruses
C
25. A _____
virus can produce a
prophage a.lytic b.lysogenic c,either lytic or lysogenic
b
26. Viral-mediated transfer of bacterial DNA a.does not occur b.is transformation
c.is conjugation d.is transduction e.none of these
d
27. A Bam H1 cleavage site exists within the “Tet” gene of pBR 322.
Following cloning and transformation, recombinants will be a.ampicillin
sensitive b.tetracycline sensitive c.chloramphenicol resistant d.tetracycline
resistant e.none of these
b
28. One of the advantages to working with E coli as a cloning vector
is the fact that E. coli does not produce human toxins a.true b.false
b
29. Which will generally proliferate most rapidly? a.bacterium
b.mammalian cell c.bacteriophage d.mammalian virus e.yeast
C
30. Enzymes exist within E. coli that will accomplish reverse
translation. a.true b.false
b
31. In a high concentration of tryptophan, the ribosome will move
through the attenuator a.rapidly b.slowly
a
32. When presented with both sugars, E. coli will use _____first. a.
glucose b. lactose
a
33. Which encodes the toxin produced during lysogenic conversion?
a.bacterium a.mammalian cell c.yeast d.virus e.none of these
d
34. Which contains the “anticodon”? a.DNA b.mRNA c.ribosome d.rRNA
e.none of these
e
35. ______
often contains a
capsule a.E. coli b.S. aureus c.Pseudomonas d.Azotobacter e.none of these
d
36. When viewing under “high” power, the object is magnified a total
of X. a.50 b.100 c.400 d.1000 e.none of these
C
37. The compound Xgal is used to detect a.the presence of a virus
b.an antibody c.a radioisotope d.a colony able to synthesize tryptophan e.a
colony’s able to use lactose
e
38. “Finding the right clone” involves a.use of antibodies
b.autoradiography c.colony hybridization d.visual inspection e.could be any of
these
e
39. Give causative agents for:
Meningitis
Plague
Pseudomembranous enterocolitis
Rheumatic fever
Rocky Mountain spotted fever
C.menin;Y.pestis;C.dificile;Strep.pyogenes;R.rickettsii
40. Give causative agents for:
Diphtheria
Epiglottitis
Gonorrhea
His toplasmos is
Impetigo
C.diph,H.infl,N.gon,H.cap,S.pyo or S.aureus
41. RNA can hybridize with single-stranded DNA. Recognition also
occurs between specific sequences in nucleic acids and certain proteins. a.true
b.false
a
42. The best way to work out the sequence of a long stretch of DNA
is a.using hybridization b.starting at one end and progressing to the other
c.using a single restriction endonuclease to create pieces that can be
sequenced and put in order d.using more than one restriction endonuclease to
create overlapping pieces e.looking at DNA binding proteins
d
43. Rolling circle replication can be used by a.eucaryotes
b.bacterial conjugation c.bacterial viruses d.all of these e.two of these
e
44. In a nucleosome, DNA is wound around a.histones b.mRNA c.tRNA
d.rRNA e. ribosomes
a
45. ______have extracellular forms a.plasmids b.mitochondria
c.chloroplasts d.viruses e.two of these
d
46. Rifamycins inhibit a.ribosomes b.restriction endonucleases c.cell
wall synthesis d.RNA polymerase e.none of these
d
47. Ribozymes most often a.synthesize RNA b.catalyse catabolic
reactions c.catalyse anabolic reactions d.transcribe DNA e.splice RNA
e
48. A start codon followed by a long series of bases before a stop
codon represents a(n) a.plasmid b.intron c.consensus sequence d.open reading
frame e.none of these
d
49. Most overlapping genes occur in a.plasmids b.bacteria c.viruses
d.eucaryotes e.none of these are more often involved with overlapping genes
C
50. When glucose is present in an E.coli cell, the concentration of
cAMP is low and binding of RNA polymerase to the lac promoter does not occur
very efficiently. a.true b.false
a
51. Some viral genomes contain both DNA and RNA. a.true b.false
b
52. Some cancers are induced by viral infections. a.true b.false
a
53. Virus receptors a.are designed to resist viral attachment b.are
transport proteins c.are involved in motility d.are involved in ATP generation
e.carry out normal cellular functions
e
54. A viral genome integrated into the host genome is a(n) a.virion
b.temperon c.prion d.prophage e.none of these
d
55. In the bacteriophage lambda, transcription of cro tends to
result in a.lysogeny b.the lytic cycle
b
56. Formation of a duplex nucleic acid molecule with strands derived
from different sources by complementary base pairing is a.autoradiography
b.ligation c.transcription d.hybridization e.Southern Blotting
d
57. An enzyme which recognizes and makes double-stranded breaks at
specific DNA sequences is a(n) a.ribozyme b.topoisornerase c.reverse
transcriptase d.DNA ligase e.restriction enzyme
e
58. In eucaryotes, translation occurs in the a.nucleus b.cytoplasm
c.sex pilus d.both nucleus and cytoplasm e.cell membrane
b
59. The DNA in E. coli would be about 1,000 times longer if not for
a.histone proteins b.ribosomes c.the endoplasmic reticulum d.the nuclear
membrane e.supercoiling
e
60. If the DNA of an organism has a high G+C content, its melting
temperature will tend to be a.high b.low
a
61. In agarose gel electrophoresis, a longer molecule will generally
move more rapidly through the gel than will a shorter molecule a.true b.false
b
62. In the ________ technique
for DNA sequencing, chemicals are used to selectively break the DNA at each of
the four nucleotide bases. a.Southern b.Northern c.Sanger d.Maxam—Gilbert
e.none of these
d
63. “Leading” and “lagging” strands are formed during a.RNA processing
b.protein synthesis c.bacteriophage attachment d.bacterial mating e.DNA
replication
e
64. A(n) _____
is involved in RNA
processing. a.ribosome b.histone c. spliceosome d.repressor e.DNA ligase
C