Derek is a gymnast, and his favorite event is the rings. To score well, he is required to hold a position for several seconds before continuing into the next move. In his favorite move, he performs shoulder abduction to form a "T" and then holds it without moving. While Derek is holding this position, what type of contraction is his deltoid performing?

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.