BIOD 210 GENETICS
Exam MODULE 6 Questions and
Ansẉers
2026\2027 update
1. Q: What is gene regulation?
ANSWER The control of gene expression, determining when, where,
and how much of a gene product is made.
2. Q: What is an operon?
ANSWER A cluster of genes under the control of a single promoter,
transcribed as a single mRNA (found primarily in prokaryotes).
3. Q: Who proposed the operon model?
ANSWER François Jacob and Jacques Monod.
4. Q: What is the function of a repressor protein in an operon?
ANSWER It binds to the operator region to block RNA polymerase
from transcribing the genes.
5. Q: Is the lac operon inducible or repressible?
ANSWER Inducible (it is normally "off" and is turned "on" by the
presence of lactose).
, 6. Q: What is the inducer of the lac operon?
ANSWER Allolactose (an isomer of lactose), which binds to and
inactivates the repressor.
7. Q: What is positive control of the lac operon?
ANSWER The CAP-cAMP complex binds to the promoter to help RNA
polymerase bind efficiently, occurring when glucose is low.
8. Q: Is the trp operon inducible or repressible?
ANSWER Repressible (it is normally "on" to make tryptophan, but is
turned "off" when tryptophan levels are high).
9. Q: In the trp operon, what is the corepressor?
ANSWER Tryptophan itself, which binds to the inactive repressor to
activate it.
10. Q: What is attenuation?
ANSWER A mechanism of bacterial gene regulation where translation
of a leader peptide affects the termination of transcription.
11. Q: What are transcription factors?
ANSWER Proteins that bind to specific DNA sequences to regulate
the rate of transcription (activators or repressors).
12. Q: What is an enhancer?
Exam MODULE 6 Questions and
Ansẉers
2026\2027 update
1. Q: What is gene regulation?
ANSWER The control of gene expression, determining when, where,
and how much of a gene product is made.
2. Q: What is an operon?
ANSWER A cluster of genes under the control of a single promoter,
transcribed as a single mRNA (found primarily in prokaryotes).
3. Q: Who proposed the operon model?
ANSWER François Jacob and Jacques Monod.
4. Q: What is the function of a repressor protein in an operon?
ANSWER It binds to the operator region to block RNA polymerase
from transcribing the genes.
5. Q: Is the lac operon inducible or repressible?
ANSWER Inducible (it is normally "off" and is turned "on" by the
presence of lactose).
, 6. Q: What is the inducer of the lac operon?
ANSWER Allolactose (an isomer of lactose), which binds to and
inactivates the repressor.
7. Q: What is positive control of the lac operon?
ANSWER The CAP-cAMP complex binds to the promoter to help RNA
polymerase bind efficiently, occurring when glucose is low.
8. Q: Is the trp operon inducible or repressible?
ANSWER Repressible (it is normally "on" to make tryptophan, but is
turned "off" when tryptophan levels are high).
9. Q: In the trp operon, what is the corepressor?
ANSWER Tryptophan itself, which binds to the inactive repressor to
activate it.
10. Q: What is attenuation?
ANSWER A mechanism of bacterial gene regulation where translation
of a leader peptide affects the termination of transcription.
11. Q: What are transcription factors?
ANSWER Proteins that bind to specific DNA sequences to regulate
the rate of transcription (activators or repressors).
12. Q: What is an enhancer?
