and CORRECT Answers
Enzyme complexes that break down protein are called _____.
lipases
ubiquitins
amylase
proteasomes
nucleases - CORRECT ANSWER - proteasomes (Proteasomes are enzyme complexes that
break down proteins.)
The nuclear membrane's role in the regulation of gene expression involves _____.
protein activation
translation
protein degradation
regulating the transport of mRNA to the cytoplasm
RNA processing - CORRECT ANSWER - regulating the transport of mRNA to the
cytoplasm (This is the role of the nuclear membrane in the regulation of gene expression.)
What is the function of a spliceosome?
protein activation
translation
protein degradation
regulating the transport of mRNA to the cytoplasm
RNA processing - CORRECT ANSWER - RNA processing (Spliceosomes are involved in
RNA processing.)
,Protein-phosphorylating enzymes' role in the regulation of gene expression involves _____.
protein activation
translation
protein degradation
regulating the transport of mRNA to the cytoplasm
RNA processing - CORRECT ANSWER - protein activation(Proteins are often activated
by phosphorylation.)
Which statement(s) about inducible operons is/are correct?
In an inducible operon, the repressor is synthesized in an active form.
In an inducible operon, an inducer inactivates the repressor.
Inducible enzymes generally function in synthetic pathways that produce end products from raw
materials. - CORRECT ANSWER - In an inducible operon, the repressor is synthesized in
an active form.
In an inducible operon, an inducer inactivates the repressor.
(An inducible operon is usually off but can be turned on when an inducer interacts with and
inactivates the repressor. The enzymes in an inducible operon generally function in catabolic
pathways. Read about inducible operons.)
Which statement(s) about repressible operons is/are correct?
In a repressible operon, the repressor is synthesized in an active form.
Repressible operons usually contain genes that code for anabolic enzymes.
,A repressible operon is on unless a co-repressor is present. - CORRECT ANSWER -
Repressible operons usually contain genes that code for anabolic enzymes.
A repressible operon is on unless a co-repressor is present.
(A repressible operon is usually on but can be turned off when a co-repressor interacts with and
activates the repressor. The enzymes in an inducible operon generally function in anabolic
pathways. Read about repressible operons.)
How are genes coordinately controlled in eukaryotic cells?
Coordinately controlled genes in eukaryotic cells share a set of control elements.
Coordinately controlled genes in eukaryotic cells are activated by the same chemical signals.
Coordinately controlled genes in eukaryotic cells are located together on the same chromosome.
- CORRECT ANSWER - Coordinately controlled genes in eukaryotic cells share a set of
control elements.
Coordinately controlled genes in eukaryotic cells are activated by the same chemical signals.
(In eukaryotes, specific transcription factors bind to control elements, promoting transcription of
coordinately controlled genes, even if the genes are on separate chromosomes. Read about
coordinately controlled genes in eukaryotes.)
The operon model of the regulation of gene expression in bacteria was proposed by _____.
Watson and Crick
Franklin
, Darwin
Jacob and Monod
Mendel - CORRECT ANSWER - Jacob and Monod
In 1961 Jacob and Monod proposed the operon model of gene regulation.
Which of these is NOT a component of the lac operon?
lactose-utilization genes only
promoter only
regulatory gene only
operator only
promoter and operator - CORRECT ANSWER - regulatory gene only
The regulatory gene, while not a part of the operon, plays a role in regulating the expression of
the genes of the operon.
Regulatory proteins bind to _____.
the operator
the lactose-utilization genes
the regulatory gene
RNA polymerase
transcription factors - CORRECT ANSWER - the operator
Transcription is inhibited when a regulatory protein binds to the lac operon operator.
In the presence of a regulatory protein the lac operon is _____.