It is important to keep the respiratory system clear so oxygen can keep flowing into your body. If something gets in your nose and irritates, you . If something gets in your nose and irritates it, you. If something gets in your trachea or bronchi and irritates it, you. Finally, if the brains thinks you are not getting enough oxygen, then it forces you to .

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.