Download Quiz 01_KEY

Biology 260 – Spring 2014
North Seattle College
NAME: _______KEY_______________
GROUP QUIZ 01
(
/40)
You have been called in to investigate a possible disease outbreak in a healthcare facility of uncontrollable
laughing, where patients suddenly start laughing at the word “poop,” double over in hysterics, cannot catch their
breath, and show evidence of loud and inappropriate behavior. Public health officials are concerned that this
may be infectious.
1.
A) What does “endemic” mean? (1) constantly present in a population
B) What does “epidemic” mean? (1) level of disease higher than expected in a population (unusually
above the endemic level)
C) What evidence would you need to determine whether this is an epidemic instead of an endemic level
of disease? (1) Expected number of cases (endemic level) compared to current number of cases
in a population. If current number of cases is unusually higher (above a threshold) than could be an
epidemic. Note that endemic level may be very high (Malaria is endemic in many countries around the
world, and there is a VERY high number of cases in many of these countries), or it may be low to absent
(Measles is no longer endemic in the United States, so even one case of measles is considered above a
threshold. When one case of measles becomes 2 cases of measles in the US, this is often referred to as
an “outbreak” which is the same as an epidemic, but is not as alarming as an epidemic).
After further examination of these patients with this terrible laughing disease, a clinical microbiologist was
finally able to isolate and identify the rare bacterium Hystericus laughicus from the patients’ stool samples
(poop). Now that it is identified, you can work on trying to find out the source of the outbreak and how it is
transmitted.
2. Name two types of reservoirs of infection that you would test in the healthcare facility to find a possible
source of the bacteria. (2) other patients, healthcare workers, healthcare environment
3. Based on the above information:
A. What do you suspect is the route of transmission of this pathogen? (1)
Since the bacteria was found in stool samples (poop), this is likely transmitted by fecal-oral route.
B. What would be the likely portal of exit of this pathogen (name a body part)? (1)
anus
C. What would be the likely portal of entry for this pathogen (name a body part)? (1)
mouth
4. In your experiments, you find that several healthcare workers in the unit where the disease first appeared
have antibodies against Hystericus laughicus, but have never shown signs of the disease. However, the
presence of the antibodies suggest that these healthcare workers have been infected with these bacteria!
How can they be infected and not show signs of disease? (2)
They are asymptomatic carriers (a human reservoir) of the disease.
5. Additional testing revealed that the bacteria were found on many different fomites throughout the facility.
What method of disease transmission would you suspect? (1) indirect transmission
6. Name and describe two Standard Precautions that you would implement in order to prevent further
transmission of this disease. (2) From many to choose: hand hygiene; care of environment, PPE, etc…
7. Which of the following is (are) considered prokaryotic cells? Circle all that apply. (1)
A. fungi
B. algae
C. protozoa
D. bacteria
E. viruses
8. Viruses differ from most bacteria in that they (1)
A. are obligate intracellular parasites
B. are able to replicate outside of a host cell and generate their own ATP
C. have a protein coat called a capsid
D. are considered living infectious agents
E. all of the above
F. A, B, and C
G. A and C
9. The general structure of a gram-negative cell wall is (1)
A. a thick layer of peptidoglycan
B. a thick layer of peptidoglycan and an outer membrane
C. a thin layer of peptidoglycan and an outer membrane
D. no peptidoglycan with an outer membrane
10. Bacterial pili function to (1)
A. allow the cell to divide
B. allow the cell to adhere to the surface of other cells
C. allow the cell to move by chemotaxis
D. allow the cells to move by Brownian motion
E. none of the above
11. Bacterial endospores (1)
A. allow cells to survive in harsh conditions, such as boiling
B. are formed inside the living bacterial cell
C. allow cells to move using chemotaxis
D. are found in bacteria from the genus Clostridium
E. A and D
F. B and D
G. C and D
H. A, B, and D
12. Draw a picture of a protein with tertiary structure and what that protein would look like once it had been
denatured. Indicate whether the denatured protein is functional or not. Be sure to label the following in your
drawing: covalent bonds, hydrogen bonds, alpha-helix, beta-pleated sheet (6)
See Figure 2.17 in textbook
Solid lines are covalent bonds,
Dashed lines are hydrogen bonds
See Figure 2.19 in textbook
Hydrogen bonds are broken
Covalent bonds are NOT broken!
Non-functional
Tertiary structure protein
Denatured protein
13. Why does boiling water kill most bacteria? Specifically, what would boiling a bacterium do to its cellular
structures that are made out of protein? (2)
The heat denatures the proteins of the bacterial cell, causing the hydrogen bonds to break apart and the protein
to become non-functional. Without functional proteins, the bacterial cell cannot do the work needed to live and
dies.
14. Fill out the table below with the name of the cell structure, its function, and the biological molecules that
make it up. (14)
Name of cell structure
Function
flagella
chemotaxis
pili
Adhesion to other cells (fimbriae),
transfer genetic material (sex pili)
Prevents the cell from bursting
Cell wall
Made of protein, lipids,
carbohydrates, nucleic acids?
List all that apply
protein
protein
Protein, lipids (Gram-negative),
carbohydrates (peptidoglycan)
Protein, lipids (phospholipids)
Cytoplasmic membrane
Transport into/out of cell, site of
energy transformation, sensing the
environment
Chromosome (bacterial cells do
not have nuclei)
ribosomes
Stores genetic information
Nucleic acids (DNA)
Site of protein synthesis
Protein, nucleic acids (RNA)
endospore
Dormant cell
Protein, lipids, nucleic acids,
carbohydrates