Lac/Trp Operon
True or False: Transcription of genes can only be repressed (decreased), not activated (increased).
False
Where do Regulatory Proteins normally bind on double stranded DNA to alter gene expression?
* 3' End
* 5' End
* Major Groove
* Minor Groove
Major Groove
Which step of PCR is used to denature the double stranded DNA into single stranded DNA molecules?
a. High Temperature (95C) b. Intermediate Temperature (72C) c. All the answers are correct d. Low Temperature (65C)
a. High Temperature (95C)
Which of the following is NOT a possible modification of histones?
a. Methylation, b.Phosphorylation c. Acetylation, d. Helication
d. Helication
What enzyme is responsible for catalyzing the phosphodiester bond between two DNA molecules?
a. Litigase, b. Reverse Transcriptase, c. Restriction endonuclease, d. Ligase
d. Ligase
For the lac operon, allolactose (a lactose metabolite) is best described as ___.
Inducer
What enzyme is responsible for catalyzing the formation of a DNA molecule based on the sequence of an RNA molecule?
a. Litigase, b. Reverse Transcriptase, c. Restriction endonuclease, d. Ligase
b. Reverse Transcriptase
Which step of PCR is used to let primers bind to the target DNA?
a. High Temperatuure(95C), b. Low Temperature(65C) c. Intermediate Temperature(72C), d. All of the answers are correct
b. Low Temperature(65C)
True or False: The binding of an activator onto the DNA can cause the DNA to bend and affect transcription initiation for a promotor found elsewhere on the DNA.
True
Which molecules do Restriction Endonucleases cleave? Choose ALL correct answers
a. DNA, b. Protein, c. RNA, d. Lipids
a. DNA
When Glucose levels are high in a bacterial cell, what are the cAMP levels?
High, Low, There is no cAMP in bacterial cells, Impossible to tell
Low
For transcription initiation of mRNA coding genes in eukaryotic organisms, which is NOT a part of the complex that forms near the promotor?
a. RNA Polymerase III, b. TAFs, c.TFIID, d.RNA Polymerase II
a. RNA Polymerase III
Which step of PCR is used for the DNA Polymerase to synthesize new DNA?
a. High Temperatuure(95C), b. Low Temperature(65C) c. Intermediate Temperature(72C), d. All of the answers are correct
c. Intermediate Temperature (72C)
True or False: An entire X chromosome can be inactivated when Xist RNA coats it, leading to histone modification.
True
True or False: All restriction endonucleases leave overlaps after cutting, leaving “sticky ends”.
False
Which conditions would the Lac Repressor bind the Operator of the lac operon? Choose ALL that apply.
a. Presence of glucose and lactose, b. Absence of glucose and presence of lactose, c. Presence of glucose and absence of lactose, d. Absence of Glucose and lactose.
C and D
True or False: cDNA molecules contain both introns and exons.
False
Why is Taq Polymerase used in PCR? Select the BEST answer
a. It can be heated to high temperature without denaturing, b. It only works in test tubes, c. It is not used in PCR, d. It is the only polymerase that replicates DNA
a. It can be heated to high temperature without denaturing
True or False: All gene expression control happens at transcription initiation.
False
A cloning vector does NOT contain which of the following?
a. a selectable marker, like antibiotic resistance, b. a gene for ribosomes, c. a sequence for replication in a host organism, d. sequences that allow DNA fragments to be added (multiple cloning site)
b. a gene for ribosomes
What conditions would the Trp Repressor bind the Operator of the Trp operon? Choose ALL that apply. a. Presence of tryptophan b. Presence of lactose and absence of tryptophan c. Absence of tryptophan d. Presence of glucose and absence of tryptophan
a.Presence of tryptophan
When running a DNA sample in gel electrophoresis, which electrode does the DNA migrate toward?
a. Negative electrode, b. Both electrodes, c. Neither electrode, d. positive electrode
d. positive electrode
What molecule would you use as a template to use Quantitative RT-PCR for identifying the quantity of gene expression in different cell types?
a. Isolated chromosomal DNA, b.Isolated mRNA, c.Any of the following molecules, d. Isolated cellular ribosomes
b.Isolated mRNA
True or False: The binding of an activator onto the DNA can cause the DNA to bend and affect transcription initiation for a promotor found elsewhere on the DNA.
True
Which of the following molecules is processed by Dicer and then loaded into RISC to target the cleavage of mRNA in the cell? Choose ALL correct answers.
a. mRNA, b. miRNA, c. rRNA, d. siRNA
b. miRNA & d. siRNA