Virulence
a) can result from selection forrapid replication within hosts.
b) is always the product of director indirect selection for host harm.
c) should always evolve to decreasein viral populations.
d) is favored because it increasestransmission rates between hosts.
e) results from antagonsisticepistasis with senesence.
f) none of the above
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QUESTION 1: The rabies virus primarily affects the nervous system. The specificity that the rabies virus has for neuronal host cells is primarily dictated by __________________________.
| A. the helical shape of its viral capsid |
| B. the type of nucleic acid used for its viral genome (single-stranded, antisense RNA) |
| C. the spikes that protrude from its viral envelope |
| D. the segmented nature of its viral genome |
QUESTION 2: Which of the following genome types has been observed in viruses? To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.
| A. Single-stranded RNA |
| B. Single-stranded DNA |
| C. Double-stranded RNA |
| D. Protein-based |
QUESTION 3: Choose the correct statement about viral evolution.
| A. RNA and DNA viral genomes evolve at equal rates. | ||||||||||||
| B. Cellular genomes mutate at a faster rate than viral genomes due to their large size and increased chance of replicative mistakes. | ||||||||||||
| C. DNA viruses mutate faster than RNA viruses because thymine is more susceptible to mutation than uracil. | ||||||||||||
| D. RNA viruses mutate faster than DNA viruses due to a lack of proofreading replicative enzymes. QUESTION 4: Your elderly patient is affected by shingles. After careful observation, you note that the virus responsible for the infection has an icosahedral capsid, is enveloped, and has double-stranded linear DNA as its genetic material. Based on this information, in which of the following viral families would you group this viral pathogen?
QUESTION 5: Which of the following is a key difference between lytic and lysogenic bacteriophage replication cycles?
|
1.
Which of the following have been used by scientists to determine evolutionary relationships and divergence times between primate species or lineages?
| A. | evidence from the fossil record | |
| B. | behavioral observations of living primates | |
| C. | molecular phylogenies | |
| D. | all of the above | |
| E. | A and C are correct |
2.
Problems with interpreting information from the fossil record include:
| A. | variation within one species may be misinterpreted (e.g. as multiple species rather than one) | |
| B. | differential preservation results in sample fossil populations which donât reflect the size of past populations | |
| C. | a species sometimes has to be defined on the basis of only one fossil specimen | |
| D. | all of the above | |
| E. | none of the above; scientists donât find any problems with interpreting fossils because the evidence is always so clear and unquestionable |
3.
Cultural practices - such as those pertaining to agriculture - can play a significant role in influencing the evolution of infectious disease microbes.
True
False
4.
Populations that evolved to include high numbers of individuals with the "thrifty genotype" include higher frequencies of the following health problems:
| A. | influenza | |
| B. | obesity | |
| C. | diabetes | |
| D. | all of the above | |
| E. | B and C are correct |
5.
Human behavior is one of the critical factors that contribute to the evolution of more virulent (harmful) bacterial and viral strains.
True
False
6.
Large agricultural and urban populations may be more vulnerable to infectious disease due to their:
| A. | larger population size | |
| B. | larger homes and dwelling structures | |
| C. | sedentary lifestyle | |
| D. | all of the above | |
| E. | both A and C are correct |