Operons

What types of cells have operons? 

• Eukaryotes

• Prokaryotes

• Neither eukaryotes nor prokaryotes

• Both eukaryotes and prokaryotes

Match the following genetic regions to their roles:

• Genes of Operon

• Place where transcription begins

• Regulatory gene

• The on/off switch where the repressor protein binds

• Operator

• Codes for the main protein / enzymes

• Promotor

• Makes a repressor protein

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

• promoter

• repressor

• operator

• gene

What is 1 in the diagram?

• RNA polymerase

• Inducer

• Repressor

• Operator

What is 2 in the diagram?

• RNA polymerase

• Inducer

• Repressor

• Operator

What is 4 in the diagram?

• RNA polymerase

• Inducer

• Repressor

• Operator

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

• lactose is absent in the cell

• galactose is present in the cell

• lactose is present in the cell

• glucose is absent in the cell

Tags

NGSS.HS-LS3-1

The trp operon in E. Coli is responsible for making 5 polypeptides involved in the tryptophan synthesis pathway. When tryptophan is present, it combines with the repressor protein to block the operator. What type of operon is trp?

• Repressible

• Inducible

The operon model was discovered in E. Coli and is almost exclusively found in ​ (a)   .

• prokaryotes

• eukaryotes

For a repressible operon to be transcribed, which of the following must be true?

• corepressor must be present.

• RNA polymerase and the active repressor must be present.

• RNA polymerase must bind to the promoter, and the repressor must be inactive.

• RNA polymerase cannot be present, and the repressor must be inactive.