1. In metagenomic studies, 16S rRNA is used to:
A. Determine the function of a gene
B. Identify species of bacteria
C. Find novel antibiotics
D. Culture microorganisms that cannot be cultured using other methods
2. Ice-minus bacteria protect plants from frost damage primarily via:
A. Competition with wild type bacteria
B. Induced systemic resistance, which stimulates the plant to produce protective compounds
C. Improving plant nutrition
D. Raising the temperature on the surface of the plant
3. According to the Great Plate Count Anomaly:
A. Viruses are easier to culture than bacteria
B. Viruses are more difficult to culture than bacteria
C. Only a small percentage of bacteria can be cultured in laboratory media
D. Pure cultures are needed to study the characteristics of particular species of bacteria.
4. Genetically engineered rennin (also called chymosin):
A. Is necessary for the production of yogurt
B. Is based on a gene normally expressed in the stomach of a calf
C. Catalyzes the production of alcohol
5. Pulsenet is a network of DNA-detecting laboratories whose purpose is to:
A. Identify novel antibiotics
B. Identify novel vaccines
C. Reduce the loss of genetic variation in crop plants
D. Aid in identifying common sources of foodborne disease
6. One microorganism produces a substance that kills a potential plant pathogen in the soil.
The relationship between these two microorganisms may be called:
A. Host shifting
B. Induced systemic resistance
C. Selective toxicity
D. Antagonism
7. Which of the following are prokaryotes?
A. Bacteria
B. Viruses
C. Fungi
D. A and B
E. A and C
F. B and C
8. Which of the following scientists is credited with developing modern bacteria culture techniques (using agar-based solid media and Petri dishes)
A. Robert Koch
B. Louis Pasteur
C. Robert Hooke
D. Antoni von Leeuwenhoek
9. In bioremediation, molecules called xenobiotics:
A. Are very soluble in water
B. Are different in structure from naturally-occurring molecules
C. Are biodegraded relatively rapidly
D. Are produced by many species of bacteria
10. Generally speaking, fermented food is _______ than the raw food from which it was produced:
A. Easier to transport
B. Harder to digest
C. More perishable
D. Less flavorful
11. Which of the following actions would be useful in speeding up the breakdown of oil on the surface of rocks?
A. Pumping in oxygen
B. Adding a carbon sources
C. Decreasing temperature to stabilize enzymes
D. Adding nitrogen and phosphorous sources
12. Substances that undergo biomagnification include those that:
A. Are excreted by animals
B. Biodegrade rapidly in the environment
C. Stimulate the production of xenobiotics
D. Increase in concentration as they move through a food chain
13. Species richness:
A. Refers to (genetic) variety within a species
B. Is generally harmful to the functioning of an ecosystem
C. Refers to the number of species in a given area
D. Is increased by modern agricultural practices
14. In the process of sewage treatment, which of the following substances is only removed in tertiary treatment, which is not part of all sewage treatment systems:
A. Organic material
B. Pathogens
C. Nitrogen and phosphorous
D. Petroleum products
15. If you wished to increase the rate of a reaction that is catalyzed by an enzyme with a thermal tolerance range of 40 to 60oC and a pH tolerance range from 5.0 to 7.0, which of the following steps might you take? (Circle all that apply. Five points total, with each step scored independently.)
A. Raising the temperature of the reaction vessel from 45oC to 55oC (assuming that the product is stable at the new temperature)
B. Altering the enzyme’s active site to allow the product to be released faster
C. Removing the product from the reaction vessel as it is formed
D. Decreasing the pH in the reaction vessel from 5.5 to 4.5 (assuming the product is stable at the new pH)
E. Decreasing the concentration of substrate to increase competition among enzymes
MATCHING. Write the letter corresponding to the best answer in the blank beside the question.
For each section, answers may be used once, more than once, or not at all.
Part II. Metagenomics
A. Sequence-based metagenomics
B. Function-based metagenomics
C. Both strategies
D. Neither strategy
____ Require(s) a host organism to express a gene
____ Involve(s) comparing a newly-acquired sequence of DNA to sequences that are already in a database in order to predict a gene’s function
____ Can be used to study organisms that cannot be cultured
Part III. Genetic exchange in bacteria
A. Transduction
B. Transformation
C. Conjugation
____ Viruses introduce DNA from one bacterium into another
____ Requires physical contact between two bacterial cells
____ Important in the spread of antibiotic resistance (which is encoded on plasmids)
____ DNA from dead bacteria (“naked DNA”) can be taken up via this process