BSC 1005 Exam #3 Study Guide UPDATED
ACTUAL Exam Questions and CORRECT
Answers
Gene Regulation - CORRECT ANSWER - ability for an organism to control which genes
are are transcribed in response to the environment
Gene Expression * - CORRECT ANSWER - Conversion of the information encoded in a
gene first into messenger RNA and then to a protein.
lac is an - CORRECT ANSWER - operon
Operon * - CORRECT ANSWER - Cluster of related genes & sequences that control gene
regulation.
The site where RNA polymerase attaches & initiates transcription is ________. * - CORRECT
ANSWER - the promoter
The _______ located between the promoter and operon, acts as a switch that is turned on or off,
spending on whether a specific protein is bound there. * - CORRECT ANSWER -
Operator.
Describe an operon on its off mode (Gene Regulation) - CORRECT ANSWER - 1.
Transcription is stopped when a repressor binds to the operator.
2. The repressor physically binds to the operator. , blocking the attachment of RNA polymerase
Describe an Operon on it's on mode (Gene Regulation in Bacteria) - CORRECT
ANSWER - 1. A lactose molecule for ex, binds to a repressor, changing the shape of the
repressor.
2. Since there is nothing no longer blocking RNA Polymerase, it binds to the promoter.
, 3. RNA transcribes genes of the lactose enzymes into mRNA.
X Chromosome Activation - CORRECT ANSWER - only one X chromosome in females
is activated (occurs in inner cell mass)
________ , collection of proteins acting together to bind to DNA sequences called enhancers and
to the promoter. - CORRECT ANSWER - Transcription factors.
During gene regulation in eukaryotic cells Repressor proteins called ___________ inhibit the
start of transcription. - CORRECT ANSWER - Silencers
__________ are proteins that turn ON genes by binding to DNA. - CORRECT ANSWER -
Activators
Alterative mRNA splicing - CORRECT ANSWER - Producing multiple mRNA from the
same gene. They will ultimately code for different polypeptides.
what exactly is cell signaling? - CORRECT ANSWER - The process of cell-to-cell
communication mediated by signaling molecules and membrane receptors
Signal Transduction Pathway - CORRECT ANSWER - a series of molecular changes that
convert a signal on the target cell's surface to a specific response within the cell; crucial to many
cellular functions
Explain the Process of Cell Signaling - CORRECT ANSWER - 1) The signaling cell
secretes a signal molecule.
2) The molecule binds to a specific receptor protein, embedded on the outside of the other cell's
membrane.
3)The bond activate a signal transduction pathway consisting of relay proteins that activate the
next one.
4) The last relay protein activates a transcription factor that triggers transcription of a specific
gene.
ACTUAL Exam Questions and CORRECT
Answers
Gene Regulation - CORRECT ANSWER - ability for an organism to control which genes
are are transcribed in response to the environment
Gene Expression * - CORRECT ANSWER - Conversion of the information encoded in a
gene first into messenger RNA and then to a protein.
lac is an - CORRECT ANSWER - operon
Operon * - CORRECT ANSWER - Cluster of related genes & sequences that control gene
regulation.
The site where RNA polymerase attaches & initiates transcription is ________. * - CORRECT
ANSWER - the promoter
The _______ located between the promoter and operon, acts as a switch that is turned on or off,
spending on whether a specific protein is bound there. * - CORRECT ANSWER -
Operator.
Describe an operon on its off mode (Gene Regulation) - CORRECT ANSWER - 1.
Transcription is stopped when a repressor binds to the operator.
2. The repressor physically binds to the operator. , blocking the attachment of RNA polymerase
Describe an Operon on it's on mode (Gene Regulation in Bacteria) - CORRECT
ANSWER - 1. A lactose molecule for ex, binds to a repressor, changing the shape of the
repressor.
2. Since there is nothing no longer blocking RNA Polymerase, it binds to the promoter.
, 3. RNA transcribes genes of the lactose enzymes into mRNA.
X Chromosome Activation - CORRECT ANSWER - only one X chromosome in females
is activated (occurs in inner cell mass)
________ , collection of proteins acting together to bind to DNA sequences called enhancers and
to the promoter. - CORRECT ANSWER - Transcription factors.
During gene regulation in eukaryotic cells Repressor proteins called ___________ inhibit the
start of transcription. - CORRECT ANSWER - Silencers
__________ are proteins that turn ON genes by binding to DNA. - CORRECT ANSWER -
Activators
Alterative mRNA splicing - CORRECT ANSWER - Producing multiple mRNA from the
same gene. They will ultimately code for different polypeptides.
what exactly is cell signaling? - CORRECT ANSWER - The process of cell-to-cell
communication mediated by signaling molecules and membrane receptors
Signal Transduction Pathway - CORRECT ANSWER - a series of molecular changes that
convert a signal on the target cell's surface to a specific response within the cell; crucial to many
cellular functions
Explain the Process of Cell Signaling - CORRECT ANSWER - 1) The signaling cell
secretes a signal molecule.
2) The molecule binds to a specific receptor protein, embedded on the outside of the other cell's
membrane.
3)The bond activate a signal transduction pathway consisting of relay proteins that activate the
next one.
4) The last relay protein activates a transcription factor that triggers transcription of a specific
gene.
