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Question
Explain why organisms undergoing rapid evolutionary change often contain relatively large numbers of mobile DNA elements, whereas once organisms settle into a stable evolutionary niche, most of these mobile elements are lost.Answer
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The immune response is as important as or even more important than antibiotics in the elimination of Bordetella pertussis from the body.
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B) chancre.
C) lesion.
D) pustule.
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Pus formation in skin lesions caused by Staphylococcus aureus infections is in part due to production of
A) coagulase.
B) hemolysins.
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The most common infectious disease(s) is/are
A) gonorrhea.
B) influenza.
C) hepatitis.
D) colds.
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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 is the causal agent of gastric ulcers?
A) Staphylococcus aureus
B) Escherichia coli O157:H7
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Which of the following statements about chlamydial infections is TRUE?
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B) Chlamydial diseases are less prevalent than gonorrhea.
C) Chlamydial diseases can lead to acute complications.
D) All of the statements are true.
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The Spanish flu of 1918 was caused by an ________ influenza virus.
A) H2N1
B) H5N1
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D) H2N2
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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.
C) of herd immunity.
D) vehicles can be sterilized.
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In just over a decade of efforts, the World Health Organization (WHO) eradicated smallpox by using worldwide
A) education campaigns.
B) destruction of infected domestic animals.
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In 2003, the majority of AIDS deaths occurred in
A) South America.
B) North America.
C) Europe.
D) Sub-Saharan Africa.
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The study of the occurrence, distribution, and determinants of health and disease in a population is the field of
A) microbiology.
B) immunology.
C) epidemiology.
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Filoviruses (such as Ebola virus) that cause severe hemorrhagic fevers generally have high ________ but low ________.
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.
B) spreads from a common source and could be controlled with adequate clean water and waste sanitation measures.
C) is spread through direct contact and has only a human reservoir.
D) has recently emerged due to overcrowding in urban centers.
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Influenza pandemics occur cyclically because
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B) new strains emerge due to reassortment between bird, swine, and human variants.
C) the vector is seasonal.
D) there are environmental reservoirs that release the virus during particular seasons.
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A) are generally gram-negative rather than gram-positive.
B) can be virtually any pathogenic bacterium or virus.
C) are eukaryotic rather than prokaryotic.
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The arrangement of Class II MHC proteins in pairs or trimers enhances their stability.
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A) TC
B) TH
C) B7
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________ ensures that each B cell produces only one immunoglobulin.
A) Self-activation
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The major histocompatibility complex is also called the
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A) clonal expansion.
B) antibody production.
C) complement protein activation.
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Which of the following is involved in B cell selection and tolerance?
A) clonal anergy
B) clonal deletion
C) clonal anergy and deletion
D) allelic exclusion
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Clonal anergy is a state of
A) antibody production.
B) high energy.
C) unresponsiveness.
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