Gene Regulation in Prokaryotes & Eukaryotes

Control of gene expression takes place at the level of

• Transcription

• Processing

• Translation

• All of these

A polycistronic structural gene is regulated by a common promoter and regulator gene in bacteria and is commonly termed as

• Operon

• Codon

• Genetic code

• None of these

In bacteria, genetic regulation is mostly mediated at ___ level.

• replication

• transcriptional

• post-transcriptional

• translational

What is an operon?

• A part of a ribsome

• A part of a RNA

• A unit made up of linked genes that code for proteins needed to do a specific task

• Needed for DNA replication

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

• promoter

• repressor

• operator

• gene

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

A protein that binds to the operator and blocks the RNA polymerase is called a ___.

• regulator

• repressor

• activator

• corepressor

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

• Operator

• Promoter

• Enhancer

• Origin

The lactose repressor is encoded by which of the following genes?

• Lac-A

• Lac-l

• Lac-Z

• Lac-Y

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