The virus first hypothesis, suggests that: a.
viruses evolved from the living cells
b.
viruses may have been the first self-replicating entities
c.
viruses originate from bacteria cells
d.
viruses don't evolve

b.

viruses may have been the first self-replicating entities

Explanation:

The “virus-first” hypothesis states that viruses predated cells and contributed to the rise of cellular life. A significant proportion of all the viral genomes encode for genetic sequences that lack clear cellular homologs. Presence of such virus-specific sequences provides support to their unique origin.

regulation of gene expression. gene expression can be regulated by various cellular processes with the aim to control the amount and nature of the expressed genes. these regulatory proteins bind to dna and send signals that indirectly control the rate of gene expression

explanation: