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