©FYNDLAY 2025 ALL RIGHTS RESERVED 12:36 PM A+
BIOL 191 Final Exam Fall 2025 Amherst
College. Exam Questions And Answers
|Latest 2025 | Guaranteed Pass
What is constitutive? - Answer✔Gene is not regulated, so expression is constant
What is regulated genes? - Answer✔Gene can be shut on/off and increased/decreased as a
response to some cue
Why regulate gene expression? (4) - Answer✔for efficiency and to respond to
environmental/physiological changes. Morre importantly, for cell specialization and to account
for changes over the course of development.
In which processes can you regulate gene expression? (4) - Answer✔transcription, RNA
processing, translation, and post-translational modification.
1
, ©FYNDLAY 2025 ALL RIGHTS RESERVED 12:36 PM A+
what are the three tricks that are fundamental to transcription regulation? - Answer✔1.
proteins bind to a specific part of DNA molecule, 2) proteins can change confirmation, and 3)
promoters can be regulated such that the frequency of transcription increases/decreases
Explain the model system of E.coli - Answer✔cleave lactose into glucose when glucose is absent
in the environment by making three enzymes: beta-galactosidase, lactose permease, and
transacetylase.
how are these three enzymes regulated by lactose? - Answer✔the presence of lactose increases
gene expression of these three enzymes. lactose binding to repressor causes repressor to
release so that the three genes can be transcribed. in the absence of lactose, the repressor
binds to the operator and blocks transcription. thus, lactose induces gene transcription
How do proteins bind to DNA in a specific manner? - Answer✔reach into major and minor
grooves and make non-covalent bonds with the base pairs. alpha helix specifically fits in major
groove of DNA.
2
BIOL 191 Final Exam Fall 2025 Amherst
College. Exam Questions And Answers
|Latest 2025 | Guaranteed Pass
What is constitutive? - Answer✔Gene is not regulated, so expression is constant
What is regulated genes? - Answer✔Gene can be shut on/off and increased/decreased as a
response to some cue
Why regulate gene expression? (4) - Answer✔for efficiency and to respond to
environmental/physiological changes. Morre importantly, for cell specialization and to account
for changes over the course of development.
In which processes can you regulate gene expression? (4) - Answer✔transcription, RNA
processing, translation, and post-translational modification.
1
, ©FYNDLAY 2025 ALL RIGHTS RESERVED 12:36 PM A+
what are the three tricks that are fundamental to transcription regulation? - Answer✔1.
proteins bind to a specific part of DNA molecule, 2) proteins can change confirmation, and 3)
promoters can be regulated such that the frequency of transcription increases/decreases
Explain the model system of E.coli - Answer✔cleave lactose into glucose when glucose is absent
in the environment by making three enzymes: beta-galactosidase, lactose permease, and
transacetylase.
how are these three enzymes regulated by lactose? - Answer✔the presence of lactose increases
gene expression of these three enzymes. lactose binding to repressor causes repressor to
release so that the three genes can be transcribed. in the absence of lactose, the repressor
binds to the operator and blocks transcription. thus, lactose induces gene transcription
How do proteins bind to DNA in a specific manner? - Answer✔reach into major and minor
grooves and make non-covalent bonds with the base pairs. alpha helix specifically fits in major
groove of DNA.
2
