If a person contracts pneumonia, inflammation occurs in the lobules of the lung, causing fluid leakage into the alveoli. Which of the following best describes the effect this has on gas exchange?
a. increased surface tension in the -liquid coating the alveolar surface
b. increased inspiratory effort
c. alveolar collapse
d. All of these changes can be expected if the production of surfactant is inadequate.

Which of the following processes within viral replication is the greatest source of genetic variation in rna virus populations? a) high mutation rate due to lack of proofreading of rna genome replication errors.b) transcription from the host cell rna polymerase introduces numerous mutations.c) capsid proteins from the host cell can replace the viral capsid.d) viral rna is translated by host cell ribosomes.