13 Jan 13. Viruses usually initiate infec

There are three (3) parts to the assignment.
Part A. Multiple Choice (20 questions for 1 point each)
Part B. Short Answer (4 questions for 5 points each)
Part C. Short Essay (6 questions for 10 points each)
Responses to Parts B and C must be written as complete sentences and in your own words (see
Purdue Online Writing Lab (OWL), "Paraphrase: Write in Your Own Words"
(http://owl.english.purdue.edu/owl/resource/563/02/ ). You must include complete citations in
APA style for the sources of your information. No points will be earned for answers that do not
include complete and accurate citations for the sources of information used to answer the
question or that support your answer.
Part A Multiple Choice: Select the best or most complete answer (1 point each)
1. In the lab you use the gram staining procedure, a differential staining technique, as a first step
in identifying the type of bacteria on a slide. After you carefully perform the staining
procedure, you look at the cells under the microscope and see purple rod shaped cells. This
result indicates that
a. the cells have a thick peptidoglycan layer as part of the physical structure of the
cell wall and are gram-positive bacilli.
b. the cells have a thin peptidoglycan layer as part of the physical structure of the cell
wall and are gram-positive bacilli.
c. the cells have a thin peptidoglycan layer as part of the physical structure of the cell
wall and are gram-negative cocci.
d. the cells have a thin peptidoglycan layer as part of the physical structure of the cell
wall and are gram-negative bacilli.
e. the cells have a thick peptidoglycan layer as part of the physical structure of the
cell wall and are gram-negative bacilli.
2. Which of the following infectious diseases has (or have) been eradicated in the world?
a. polio
b. measles
c. smallpox
d. whooping cough
e. all of the above
3. Which of the followings is a characteristic of prions that is unique from other known
pathogenic microbes?

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a. They lack the characteristics of a classic cell.
b. They can be transmitted from animals to man.
c. They cause permanent damage to the host.
d. They are made entirely of protein.
4. The first microorganism demonstrated to satisfy Koch’s postulates (in the late 19th century)
was
a. Mycobacterium tuberculosis
b. Bacillus anthracis
c. Mycobacterium leprae
d. Vibrio cholera
5. Which of the following is a characteristic of the adaptive immune response and not of the
innate immune response?
a. Physical and chemical barriers
b. Clonal expansions of activated B cells
c. Inflammatory mediators
d. Phagocytosis
6. What does each codon in messenger RNA (mRNA) specify?
a. a nucleotide
b. an enzyme
c. an amino acid
d. a promoter
7. Antigens are
a. specific.
b. proteins or polysaccharides (complex sugars).
c. recognized as foreign by the body’s immune system.
d. all of the above.
8. Oncogenes are genes that
a. the virus utilizes to replicate itself.
b. transform normal cells to cancer cells.

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c. promote genetic recombination in bacteria.
d. influence ongoing protein production.
9. Genes A, B, and C are three structural genes of an operon and fall in that order within the
operon. A mutation occurs in Gene A that halts transcription early in the gene. What effect
will this have on the levels of proteins produced by Genes A, B, and C?
a. No proteins coded by genes A, B, and C will be produced.
b. Proteins coded by genes B and C, but not gene A, will be produced
c. Proteins coded by genes A, B, and C will be produced.
d. Only proteins coded by gene A will be produced.
10. Plasmids
a. replicate with the bacterial chromosome.
b. may contain antibiotic resistance genes.
c. are as large as the bacterial chromosome.
d. contain genes essential for growth.
11. Interferons are an important part of the host defense against viral infections. Their principal
mode of action is that
a. they trigger the synthesis of one or more cellular proteins that inhibit viral
replication.
b. they are present in the serum of healthy individuals and act as viral surveillance
factors.
c. they coat viral particles and block their attachment to cells.
d. they protect the death of a viral-infected cell.
12. The form of genetic exchange by which donor DNA is introduced into a recipient bacterial
cell by a bacterial virus is
a. transformation.
b. conjugation.
c. transduction.
d. transfection.
e. vertical transfer.
13. Viruses usually initiate infection by first interacting with receptors on the surface of cells.
Which of the following statements is most accurate about cellular receptors for viruses?

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