The functioning of enhancers is an example of

• transcriptional control of gene expression.

• a post-transcriptional mechanism to regulate mRNA.

Which of the following is an example of post-transcriptional control of gene expression?

• The addition of methyl groups to cytosine bases of DNA

• the binding of transcription factors to a promotor

• the removal of introns and alternative splicing of exons

A protein that binds to the operator and blocks the RNA polymerase

• regulator
• repressor
• activator
• corepressor

The "on/off" switch for an operon is called the

• promoter
• repressor
• operator
• gene

What is the name of the stretch of DNA where RNA polymerase binds?

• operator
• promoter
• enhancer
• origin

What is the role of operons in prokaryote gene expression?

• It makes the genes prokaryotes be turned on
• It accounts for the regulation of gene activity in response to the needs of the cells
• To make DNA for the gene
• To make the gene turn of and off

Operons are found in the cells of which of the following types of organisms?

• prokaryotes (bacteria)
• eukaryotes (plant and animals)
• animals only
• viruses

The production of mature mRNA in eukaryotes involves

• cutting introns out and spicing exons together
• adding the 5' cap
• adding the 3' poly A tail
• all of these are correct

Which process is shown?

• diffusion
• repiration
• recombination
• translation

What is an example of translational control of gene expression?

• activation of proteins by folding or enzymatic cleavage

• addition of chemical groups, such as phosphate groups, to free amino acids in the cytoplasm

• binding of protein factors to specific sequence in mRNA preventing ribosomes attaching

• formation of disulfide bridges in the protein being formed