Question

Which of the following statements best defines the term operon?

a. An operon is a region of DNA that consists of a single gene regulated by more than one promoter.b. An operon is a region of DNA that codes for a series of functionally related genes under the control of the same promoter.c. An operon is a region of DNA that codes for sugar-metabolizing enzymes.d. An operon is a region of RNA that consists of the coding regions of more than one gene.

Answer 1

An operon is a region of DNA that codes for functionally related genes controlled by the same promoter, such as the lac operon in E. coli which is regulated by lactose.

Step-by-step explanation:

The correct definition for an operon is option b: An operon is a region of DNA that codes for a series of functionally related genes under the control of the same promoter. An operon allows for the coordinated regulation of gene expression in prokaryotic cells. For instance, the lac operon in E. coli bacteria, includes a promoter, an operator, and genes that code for enzymes to digest lactose. The presence of lactose can regulate these genes by affecting the binding of the repressor to the operator, allowing for the transcription of these genes when lactose is available.

Answer 2

b. An operon is a region of DNA that codes for a series of functionally related genes under the control of the same promoter

Step-by-step explanation:

An operon is usually found in prokaryotic organisms. It refers to the functional structure within prokaryotic genome in which multiple different genes are under the control of one promotor. All of the genes are transcribed together which leads to the formation of polycistronic mRNA. Polycistronic mRNA migh undergo splicing to create monocistronic mRNAs which will be translated separately into few products (proteins).