BIOD 210 MODULE 4 EXAM ACTUAL TEST
PAPER 2026 QUESTIONS WITH SOLUTIONS
GRADED A+
◉ An allosteric molecule is one in which ________ Answer: Changes
the conformation of the effector thus changing the binding affinity to
that effector
◉ Loss-of-function mutations that eliminate the function of a gene
product are also known as _____ mutations or gene knockouts.
Answer: null
◉ _______________ is also known as RNA silencing and
posttranscriptional gene silencing. Answer: RNA interference
◉ When considering the binding of cAMP-CAP and RNA polymerase
to the lac operon, both bind more efficiently than either singly. What
term is applied to this increased efficiency of binding? Answer:
cooperative
◉ A catabolite-activating protein (CAP) exerts _____________control
over the lac operon. Answer: positive
,◉ How can the expression of a gene be drastiacally altered by the
presence of comparatively small numbers of RNA molecules? What
is the term for this class of gene regulation? Answer: -Term: RNAi
(RNA interference
-As a research tool, short synthetic dbl. stranded RNAi molecules are
introduced into cells where they trigger RNA degradation pathways,
which target mRNAs. This is used to knock out the function of a gene
◉ Attenuation involves the termination of ______ synthesis Answer:
mRNA
◉ This structure forms when an extra X chromosome is methylated
and largely inactivated. It is most commonly found in females.
Answer: barr body
◉ The _________ can be used to quickly screen chemicals for their
ability to be mutagenic (and hence potentially carcinogenic).
Answer: Ames Test
◉ A conditional mutation is one that allows a mutant gene product
to function normally under the ________ condition, but to function
abnormally under the ________ condition. Such mutations are
especially useful for the study of ________ mutations. Answer:
permissive, restrictive, lethal
, ◉ Genetic regulation in eukaryotes can take place at a variety of
levels from transcriptional to post-translational. At what level is
genetic regulation considered most likely in prokaryotes? Answer:
transcriptional
◉ The difference between a genetic screening experiment and a
selection experiment is that a screening experiment involves ________,
whereas a selection experiment creates conditions that ________
irrelevant organisms. Answer: visual examination; eliminate
◉ An example of a gene product encoded by a regulatory gene is
Answer: repressor protein
◉ An operon is controlled by a repressor. When the repressor binds
to a small molecule, it binds to DNA near the operon. The operon is
constitutively expressed if a mutation prevents the repressor from
binding to the small molecule. Answer: negative repressible
◉ A mutant E. coli strain, grown under conditions that normally
induce the lac operon, produces high amounts of ß-galactosidase.
What is a possible genotype of the cells? Answer: lacI+ lacP+ lacOc
lacZ+ lacY+ lacA+
◉ Which of these is a level or type of genetic regulation in
eukaryotes? Answer: DNA methylation, transcriptional, post-
translational
PAPER 2026 QUESTIONS WITH SOLUTIONS
GRADED A+
◉ An allosteric molecule is one in which ________ Answer: Changes
the conformation of the effector thus changing the binding affinity to
that effector
◉ Loss-of-function mutations that eliminate the function of a gene
product are also known as _____ mutations or gene knockouts.
Answer: null
◉ _______________ is also known as RNA silencing and
posttranscriptional gene silencing. Answer: RNA interference
◉ When considering the binding of cAMP-CAP and RNA polymerase
to the lac operon, both bind more efficiently than either singly. What
term is applied to this increased efficiency of binding? Answer:
cooperative
◉ A catabolite-activating protein (CAP) exerts _____________control
over the lac operon. Answer: positive
,◉ How can the expression of a gene be drastiacally altered by the
presence of comparatively small numbers of RNA molecules? What
is the term for this class of gene regulation? Answer: -Term: RNAi
(RNA interference
-As a research tool, short synthetic dbl. stranded RNAi molecules are
introduced into cells where they trigger RNA degradation pathways,
which target mRNAs. This is used to knock out the function of a gene
◉ Attenuation involves the termination of ______ synthesis Answer:
mRNA
◉ This structure forms when an extra X chromosome is methylated
and largely inactivated. It is most commonly found in females.
Answer: barr body
◉ The _________ can be used to quickly screen chemicals for their
ability to be mutagenic (and hence potentially carcinogenic).
Answer: Ames Test
◉ A conditional mutation is one that allows a mutant gene product
to function normally under the ________ condition, but to function
abnormally under the ________ condition. Such mutations are
especially useful for the study of ________ mutations. Answer:
permissive, restrictive, lethal
, ◉ Genetic regulation in eukaryotes can take place at a variety of
levels from transcriptional to post-translational. At what level is
genetic regulation considered most likely in prokaryotes? Answer:
transcriptional
◉ The difference between a genetic screening experiment and a
selection experiment is that a screening experiment involves ________,
whereas a selection experiment creates conditions that ________
irrelevant organisms. Answer: visual examination; eliminate
◉ An example of a gene product encoded by a regulatory gene is
Answer: repressor protein
◉ An operon is controlled by a repressor. When the repressor binds
to a small molecule, it binds to DNA near the operon. The operon is
constitutively expressed if a mutation prevents the repressor from
binding to the small molecule. Answer: negative repressible
◉ A mutant E. coli strain, grown under conditions that normally
induce the lac operon, produces high amounts of ß-galactosidase.
What is a possible genotype of the cells? Answer: lacI+ lacP+ lacOc
lacZ+ lacY+ lacA+
◉ Which of these is a level or type of genetic regulation in
eukaryotes? Answer: DNA methylation, transcriptional, post-
translational
