Download Spring 2007 - Antelope Valley College

BIOLOGY 204
GENERAL MICROBIOLOGY
INSTRUCTOR: Dr A. Hemsley
ANTELOPE VALLEY COLLEGE
Spring 2007
THEORY TEST 2
100 POINTS
STUDENT NAME: ___________________________________
STUDENT I.D. NUMBER: _____________________________
•
Perusal time = 10 minutes
•
Test time = 100 minutes
•
ANSWER ALL QUESTIONS
•
Read ALL questions carefully during perusal time, you may write if you wish.
•
Use the back of each sheet if you do not have enough writing space, but please label each answer.
•
Question subheadings are NOT of equal points value.
•
Points allocated for each subheading are shown at the end of the question.
GOOD LUCK!
QUESTION 1 (Total =10 points)
Match entries in the left column with answers from the lettered choices in the right column. Write your letter choice
to the far left of each question in the spaces provided. Use each answer only ONCE.
(1 Point per correct pair)
_____ 1. A disinfectant that is an effective degermer
a.
Iodine
_____ 2. Early antiseptic, now considered carcinogenic
b.
Autoclave
_____ 3. Halogen used extensively in municipal water treatment
c.
Bacteriostasis
_____ 4. Halogen used as an antiseptic, very effective as a tincture
d.
Virucide
_____ 5. Enzyme denaturants, some toxicity
e.
Pseudomonas
_____ 6. Prevention of bacterial growth without killing the bacteria present
f.
Hepatitis A virus
_____ 7. Instrument using pressurized steam to sterilize
g.
Ethanol
_____8. Microbe that is difficult to kill with Quaternary ammonium detergents
h.
Chlorine
_____ 9. Agent capable of killing viruses
i
Heavy metals
_____ 10.Microbe that is resistant to chlorination
j.
Phenol
(eg. mercurochrome)
page 1
QUESTION 2 (Total =10 points)
Three flasks of nutrient broth are inoculated with the same number of bacterial cells; one contains
Lactobacillus (Flask 1), one contains Streptococcus lactis (Flask 2) and one contains Micrococcus luteus
(Flask 3). Each flask is incubated at the optimum temperature for the bacteria contained inside, with ideal
nutrients and oxygenation overnight . The next morning you analyze the bacterial growth in the flasks.
Rank the flasks in order from the one with the most cells present to the one with the least cells present.
Make sure you say which has the most, and which has the least!
(3)
Rank the flasks in order from the one with the highest oxygen concentration present to the one with the
least oxygen. Make sure you say which has the most, and which has the least!
(4)
One of the cultures may contain many dead cells. Which one is it, and why are the cells dead?
(3)
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QUESTION 3 (Total =20 points)
A.
You are a hospital administrator whose responsibilities include purchasing disinfectants for hospital use.
List at least three factors you might consider when choosing between the following products:
Product A: Cost $50 per gallon, type quaternary ammonium detergent
Product B: Cost $10 per gallon, type oxidizer
(6)
B.
Explain the difference between bacteriocidal and bacteriostatic methods to control microbial growth. Give an
example of a method or agent that is bacteriocidal and one that is bacteriostatic.
(6)
C.
What is one of the advantages to using ethanol prior to surgeries or venipunctures?
D.
Provide 2 examples of using osmotic control to limit bacterial growth. Your examples will more likely come from the
food industry than the health care industry.
(3)
(3)
page 3
QUESTION 4 (Total =20 points)
Provide brief definitions for the following terms:
A.
PROMOTER
B. GENE
C.
GENE POOL
D.
RESTRICTION ENDONUCLEASE
E. SIMULTANEOUS REPLICATION FORKS
page 4
QUESTION 5 (Total =20 points)
Fill in the blanks in the following sentences. (1 point per correct sentence)
1.
The nucleotide that pairs with G in RNA is____________________________.
2.
The first amino acid in all protein molecules is____________________________.
3.
One of the three codon sequences that signal protein synthesis termination is
4.
DNA synthesis in the direction that goes directly towards the replication fork is
____________________________.
called ____________________________ strand synthesis.
5.
DNA synthesis in the direction that goes away from the replication fork is called
____________________________ strand synthesis.
6.
A DNA mutation where a base change does not affect the protein sequence of the gene product is
called a ____________________________ mutation.
7.
A DNA mutation where a base change affects one amino acid in the protein sequence of the gene
product is called a ____________________________ mutation.
8.
A DNA mutation where a base change introduces a STOP codon in the protein sequence of the gene
product is called a ____________________________ mutation.
9.
One target area of a microbe that disinfectants may injure is the____________________________.
10.
____________________________is a mechanism introduces new genetic material into a bacterium as naked DNA.
11.
____________________________ is a mechanism introduces new genetic material into a bacterium by way of a
bacteriophage vector.
12.
____________________________ is a mechanism introduces new genetic material into a bacterium due to a mating
event initiated by the F plasmid.
13.
Plasmids confer a survival advantage, such as____________________________ to bacteria possessing them.
14.
____________________________ is an enzyme that catalyses the formation of an RNA chain.
15.
The ____________________________ is an enzyme used to cut DNA at specific sequences.
16.
One important recombinant gene product expressed in bacteria is____________________________.
17.
A method of artificially introducing genes into cells is
____________________________ .
18.
A recombinant vaccine produced in yeast cells is the
____________________________.
19.
A vaccine that consists of proteins alone is known as a
____________________________.
20.
The enzyme that joins DNA fragments to one another is _____________________________.
page 5
QUESTION 6 (Total =20 points)
A.
Discuss one breakthough in medical science and one successful outcome in agriculture that have been possible through
the use of recombinant DNA technology
(8)
B.
Explain how the polymerase chain reaction has assisted forensic scientists to solve violent crimes.
include a brief description of how this technique works.
C.
Bacterial cells replicate in as little as 30 minutes, while eukaryotic cells take considerably longer. With your
newfound understanding of microbial genetics, describe three strategies that bacteria have at their disposal to assist in
rapid replication.
(6)
In your answer,
(6)
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