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Question
Describe the hypothesis of viruses occurring before living cells and how DNA might have evolved. What is the current hypothesis about the evolutionary relationships between RNA, DNA, viruses, and cellular life?Answer
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A) gonorrhea.
B) influenza.
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Which disease causes over 1.6 million deaths per year worldwide, which is approximately 11% of all deaths related to infectious diseases?
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Which of the following statements about chlamydial infections is TRUE?
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The Spanish flu of 1918 was caused by an ________ influenza virus.
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Diseases can be controlled through immunization even if the percentage of the population that is immunized is less than 100% because
A) vectors can be controlled through other means.
B) most diseases lack reservoirs.
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In 2003, the majority of AIDS deaths occurred in
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C) Europe.
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The study of the occurrence, distribution, and determinants of health and disease in a population is the field of
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A) incidence / prevalence
B) prevalence / mortality
C) mortality / morbidity
D) morbidity / mortality
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Cholera is an example of a pandemic disease that
A) has multiple wild animal reservoirs and is thus difficult to eradicate.
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C) is spread through direct contact and has only a human reservoir.
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Influenza pandemics occur cyclically because
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C) the vector is seasonal.
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B) can be virtually any pathogenic bacterium or virus.
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The arrangement of Class II MHC proteins in pairs or trimers enhances their stability.
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________ ensures that each B cell produces only one immunoglobulin.
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A) clonal anergy
B) clonal deletion
C) clonal anergy and deletion
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Clonal anergy is a state of
A) antibody production.
B) high energy.
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D) high energy and antibody production.
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An individual usually expresses ________ structurally distinct allele(s) that encode class I MHC proteins.
A) one
B) two
C) four
D) six