1. Cells must control gene expression so that

a. their genes will be expressed only when needed
b. their genes will always be expressed
c. their genes will never be expressed
d. genetic disorders can be corrected.

2. In bacteria, a group of genes that code for functionally relatedenzymes, their promoter site, and the operator that controls themall function together as a

a. exon.
b. intron.
c. operon.
d. ribosome