15 questions
Operons are found in the cells of which of the following types of organisms?
prokaryotes
eukaryotes
animals only
viruses
What is the name of the stretch of DNA where RNA polymerase binds?
operator
promoter
enhancer
regulatory gene
The "on/off" switch for an operon is called the
promoter
enhancer
operator
gene
A key advantage of grouping genes with related functions is that a single "on-off" switch can control the whole cluster.
True
False
What is a gene?
A segment of RNA that encodes for a protein
The portion of the chromosome that does not get transcribed
A segment of DNA that encodes for a protein
The collection of your chromosomes
A protein that binds to the operator and blocks the RNA polymerase
inducer
repressor
activator
corepressor
The repressor is the protein product of a(n)
operator
regulatory gene
lac gene
corepressor
The tryptophan operon is
permanently turned on.
turned on when tryptophan is present in the growth medium.
turned off only when glucose is present in the growth medium.
turned off when tryptophan is added to the growth medium.
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
tryptophan is present
The binding of repressors to operators are not reversible.
True
False
The purpose of the lac operon is to produce enzymes that
synthesize lactose
use lactose
synthesize tryptophan
use tryptophan
The lac operon is referred to as a(n) __________ operon.
inducible
repressible
audible
inaudible