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WorksheetsTranscription and Lac operon
Total questions: 20
Worksheet time: 30mins
During transcription _________
DNA is made complimentary to RNA
RNA is made complimentary to DNA
a protein is made from the RNA base sequence
a protein is made from the DNA base sequence
RNA is synthesized on a DNA template in a process called ______, which utilizes the enzyme _______
translation, RNA polymerase
transcription, DNA polymerase
transcription, RNA polymerase
replication, DNA polymerase
Given the following DNA strand, which of the following is its complementary mRNA? 3’ G G A C T G A T T 5’
3’ C C U G A C U A A 5’
5’ C C U G A C U A A 3’
5’ G G A C T G A T T 3’
3’ T T A G T C A G G 5’
Once transcription has been completed, which of the following is NOT necessary for protein synthesis to occur?
tRNA
ribosomes
mRNA
DNA
Which site of the tRNA molecule binds to the mRNA molecule?
Anticodon
Codon
amino acid
5’ end
What is the basic role of mRNA?
transfer the amino acids to the ribosome
transfer the amino acids to the nucleus
transfer the DNA message to the ribosome
transfer the mRNA message to the nucleus
What is the role of the ribosome in protein synthesis?
it is where mRNA synthesis occurs
it is where DNA synthesis occurs
it is where protein synthesis occurs
it is where gene synthesis occurs
If the DNA code reads CCAATTGG then the tRNA code would read ____________
CCAATTGG
CCAAUUGG
GGUUAACC
GGTTAACC
Introns are
Noncoding sequence of mRNA
Coding sequence of mRNA
Complex of molecules that cut out the introns and splice together the exons
Involves the removal of introns, fusing of the exons, and the addition of a 5’ cap and a Poly A tail to mRNA
All of the following is true about pre-mRNA that is produced in eukaryotes EXCEPT
Consist of intron and exon
Carry genetic information for specific protein synthesis
Will be used as template in translation process
Synthesized in nucleus during transcription
Functioning unit of DNA containing a cluster of genes under the control of a single regulatory signal or promoter is termed as
Operon
Operator
Lac
Repressor protein
Which of the following conditions leads to maximal expression of the lac operon?
lactose present, glucose absent
lactose present, glucose present
lactose absent, glucose absent
lactose absent, glucose present
Lac operon can be found in
E. coli
lactose
human colon
glucose
The structural gene that codes for protein that increase the permeability of the plasma membrane towards lactose is.
lacI
lacZ
lacY
lacA
What is the enzyme that detoxifies other molecules entering the cell via the permease?
β-galactosidase
β-galactoside primase
β-galactoside permease
β-galactoside transacetylase
What happen to lac operon in the absence of lactose?
lac operon is switched off
lac operon is active
repressor protein bind to promoter
RNA polymerase binds to operator
Which of the following is active in the absence of lactose?
lacI
lacZ
lacY
lacA
Which sentence is TRUE about structural genes in the absence of lactose?
Transcription occurred to synthesis enzyme
Translation occurred to synthesis mRNA
Transcription occurred to synthesis mRNA
No transcription and translation occurred
If a promoter was being deleted in lac operon, what would be the effect towards lac operon in the absence of lactose?
RNA polymerase can transcribe the structural genes
Enzymes are being produced
Repressor protein will change its shape
RNA polymerase cannot bind to lac operon
In the absence of glucose, the lac operon system is activated when the person consumes the following, EXCEPT
soy milk
yoghurt
cream cheese
milkshake
