Gene Expression in Prokaryotes and Eukaryotes

Which of the following can serve as an "off" switch in eukaryotic organisms?

• Histone acetylation

• DNA methylation

• Operator

• Repressor

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

The lac operon genes only become expressed if:

• lactose binds to the repressor
• glucose binds to the repressor
• lactose binds to the operator
• the repressor binds to the operator

In the lac operon model the genes within the operon will be expressed if:

• lactose is absent in the cell
• glucose is present in the cell
• lactose is present in the cell

What type of operon is the trp (tryptophan) operon?

• inducible
• repressible
• positive control
• promoible

Which of the following can serve as an "on" switch in eukaryotic organisms?

• Histone acetylation

• DNA methylation

• Operator

• Repressor

Prokaryotes regulate gene expression primarily

• in order to maintain homeostasis

• in response to changing environmental conditions

• during development as cells specialize

• Prokaryotes do not regulate gene expression. All genes are always on.

In order for a gene to be expressed, ___ must bind to the gene's ___, a specific sequence of nucleotides at one end of the gene, thus initiating transcription.

• DNA polymerase, promotor

• DNA polymerase, operator

• RNA polymerase, promotor

• RNA polymerase, operator

An operon is

• a genetic on/off switch in prokaryotes

• a genetic on/off switch in eukaryotes

• a group of related genes and the associated gene switches in prokaryotes

• a group of related genes and the associated gene switches in eukaryotes