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Question
The earliest stromatolites were probably formed byA) anoxygenic phototrophs.
B) anoxygenic lithotrophs.
C) oxygenic phototrophs.
D) oxygenic lithotrophs.
Answer
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Related questions
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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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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
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B) most diseases lack reservoirs.
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In just over a decade of efforts, the World Health Organization (WHO) eradicated smallpox by using worldwide
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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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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.
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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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Which of the following is involved in B cell selection and tolerance?
A) clonal anergy
B) clonal deletion
C) clonal anergy and deletion
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Clonal anergy is a state of
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B) high energy.
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Q:
An individual usually expresses ________ structurally distinct allele(s) that encode class I MHC proteins.
A) one
B) two
C) four
D) six