What are the necessary requirements for high levels of transcription for the lac operon?
High Lactose, low glucose, low cAMP
Low Lactose, high glucose,
... [Show More] high cAMP
High Lactose, low glucose, high cAMP
High Lactose, high glucose, low cAMP - CORRECT ANSWER High Lactose, low glucose, high
cAMP
Which of the following statements is/are correct regarding the 10 promoter from bacteriophage
T7?
When IPTG is added, it inhibits the lac repressor
In the absence of IPTG, the lac repressor represses the synthesis of T7 RNA polymerase
All are correct
The gene 10 promoter from bacteriophage T7 requires T7 RNA polymerase for transcription -
CORRECT ANSWER All are correct
Which of the following statement(s) is/are INCORRECT regarding transcription regulation?
I. The activators bind to DNA and increases transcription
II. The repressors bind to DNA molecule and inhibit transcription
III Negative control refers to transcriptional regulation by activator proteins
IV. Positive control refers to transcriptional regulation by repressor proteins
II only
III & IV
I, II, & III
I & II - CORRECT ANSWER III & IV
Which of the following is NOT a way to regulate gene expression via changes in chromatin
structure or DNA structure?
Gene rearrangement
Alternative splicing
DNA methylation
Chromatin compaction - CORRECT ANSWER Alternative splicing
DNA hemimethylation is the methylation of __________.
None are correct
Both stands of DNA
One strand of DNA
No methylation on either strand - CORRECT ANSWER One strand of DNA
What is the tac promoter in E. coli? - CORRECT ANSWER Tac is a strong promotor
constructed from the -10 region of the lac promoter and the -35 region of the trp promoter
____________________ are the two common regulatory transcription factors that enhance the
transcription in eukaryotes.
TFIIE and Rho proteins
U1 and operator proteins
TFIID and mediator proteins
Operator proteins and enhancers - CORRECT ANSWER TFIID and mediator proteins
Heterodimers are formed by two different transcription factors.
True
False - CORRECT ANSWER True
Name the three structural genes present in the lac operon. What is the role of b-galactosidase? -
CORRECT ANSWER LacZ -> encodes beta-galactosidase enzymatically cleaves lactose into
galactose and glucose
LacY
LacA
An activator protein binds to the ________________ region of DNA to promote transcription.
Repressor
Enhancer
Silencer
None are correct - CORRECT ANSWER Enhancer
Which of the following statements is INCORRECT regarding the CREB protein?
Unphosphorylated CREB protein is required to activate RNA polymerase in extracellular
signaling
The CREB protein becomes activated in response to cell-signaling molecules that increase
cAMP
CREB stands for cAMP response element-binding
The CREB protein recognizes the consensus sequence 5'-TGACGTCA-3' - CORRECT
ANSWER Unphosphorylated CREB protein is required to activate RNA polymerase in
extracellular signaling
A more widespread mechanism for RNA editing is the _______________ of bases.
Deacetylation
Deamination
Demethylation
Dephosphorylation - CORRECT ANSWER Deamination
What are SR proteins? Explain its role. - CORRECT ANSWER SR proteins are splicing factor
proteins which have domains that are rich in (S) serine and arginine(R). They have an RNAbinding domain at their N-terminal end. It is involved in protein-protein recognition which plays
a key role in choosing splice sites
What is the periplasm and explain its role? - CORRECT ANSWER 6. Region between inner and
outer E.coli membrane
1. No inclusion body formation by improved folding
2. Disulfide bridge formation by protein disulfide isomerase, disulfide oxidoreductase and
disulfide isomerase
What is codon optimization? - CORRECT ANSWER a technique recently used by many
scientists to improve the protein expression in living organism by increasing the translational
efficiency of gene of interest
Which of the following statements is correct about mRNA stability?
None are correct
Less adenosines in the poly-A-tail help protect against exonucleases and endonucleases
A length of 10-30 adenosines long help mRNA stability
The poly-A-tail is about 200 nucleotides long and protects mRNA stability - CORRECT
ANSWER The poly-A-tail is about 200 nucleotides long and protects mRNA stability
Which of the following is NOT a way to regulate gene expression via RNA processing and
translation?
RNA editing
RNA interference
RNA stability
CpG islands - CORRECT ANSWER CpG islands
Which of the following is a guide RNA organism?
Streptococcus pneumoniae
None are correct
Trypanosoma brucei
Staphylococcus aureus - CORRECT ANSWER Trypanosoma brucei
Write the antisense RNA sequence for the following RNA: CAG UAG GCC AAU - CORRECT
ANSWER GUC AUC CGG UUA
Which of the following is/are benefits of RNA interference?
Presents a newly identified form of gene regulation
May play a role in silencing certain transposable elements
All are correct
May offer a defense mechanism against certain viruses - CORRECT ANSWER All are correct
______________ is considered a primary metabolite.
Anthocyanins
Asparagine
Alkaloids
Monoterpenes - CORRECT ANSWER Asparagine
Which of the following is NOT considered a secondary metabolite?
Terpenes
Phenolic compounds
Acetyl CoA
Alkaloids - CORRECT ANSWER Acetyl CoA [Show Less]