How does the nicotine from cigarette smoking disrupt oxygen distribution to the cells? it restricts air flow through the bronchi. it reduces the surface area of alveolar sacs. it binds to hemoglobin in red blood cells . it affects the nerve signals that regulate breathing.

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.