Gene Expression and Regulation

In prokaryotes, gene expression is regulated by controlling

• transcription.

• replication.

• translation.

• processing.

The bacterial lac operon is switched on when

• the operator binds to the promoter.

• lactose binds to the lac operator.

• the operator binds to the lac genes.

• lactose binds to the lac repressor.

In a eukaryotic cell, where does mRNA processing take place?

• cytoplasm

• nucleus

• ribosome

• operator

What is the term for the nucleotide sequences that are removed during mRNA processing?

• operators

• promoters

• exons

• introns

What is the main function of a promoter?

• codes for enzymes that break down sugar

• blocks the action of RNA polymerase

• tells RNA polymerase where to start

• keeps eukaryote genes permanently “off ”