5C: Gene expression and regulation

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

• promoter

• repressor

• operator

• gene

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

An operon consists of all the the following EXCEPT

• operator

• promoter

• regulatory gene

• genes of the operon

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

• regulator

• repressor

• activator

• corepressor

A small molecule that binds to the repressor and makes it inactive is

• corepressor

• inducer

• promoter

• operator

When a gene does not transcribe unless turned on by activator , it is considered _____ control

• positive

• negative

Two types of negative control are

• repressible & inducible

• repressible & active

• active & inactive

• repressible & corepressible

Inducible negative control is when when the gene is transcribed by the ____ of a specific molecule

• presence

• absence

Repressible negative control is when when the gene is transcribed by the ____ of a specific molecule

• presence

• absence

What is an example of positive control?

• The lac operon being transcribed when lactose is present

• The trp operon being transcribed when tryptophan is absent

• the lac promoter being activated by CAP when cAMP levels rise

• control is all just an illusion