67 Questions
What is the primary function of DNA ligase in the cloning process?
It covalently joins DNA fragments together
What does the term 'cloning' refer to in the context of DNA cloning?
Making several copies of a DNA molecule
What is a recombinant DNA molecule?
A DNA molecule that contains genetic material from two different sources
What is the primary advantage of using plasmids as cloning vectors?
They can replicate independently of the host cell's genome
Which of the following is a required component of a plasmid cloning vector?
An origin of replication (OriC)
What is the purpose of including a selectable marker gene, such as an antibiotic resistance gene, in a plasmid cloning vector?
To facilitate the identification and selection of cells that have taken up the vector
What technique allows the separation of proteins based on their size?
Gel electrophoresis (SDS-PAGE)
Which of the following protein tags is a fluorescent protein that can be detected by its fluorescence?
Green fluorescent protein (GFP)
What technique involves the use of antibodies to purify a specific protein from a mixture?
Immunoprecipitation
Which of the following protein tags allows for purification using beads with bound nickel ions?
Poly-His
What technique involves the transfer of separated proteins from a gel to a membrane for detection with antibodies?
Immunoblotting
Which of the following protein tags can be purified using a peptide corresponding to its amino acid sequence?
All of the above
What is a protein domain?
A compact region of the protein's polypeptide chain with defined structure that can fold independently
What is the purpose of Green Fluorescent Protein (GFP) in proteins?
To detect the protein
What are the characteristics of a protein domain?
It is self-stabilizing, has defined structure, and can fold independently
What does GST stand for in the context of proteins?
Glutathione S transferase
Why are recombinant proteins produced?
To generate large quantities of specific proteins for research or commercial use
What is the purpose of a restriction site in the creation of recombinant DNA?
To cut the DNA fragments and allow for insertion into the plasmid
What is the purpose of a DNA ligase in the creation of recombinant DNA?
To close the plasmid and seal the inserted DNA fragment
What is the purpose of a promoter sequence in an expression vector?
To drive the expression of the inserted gene
What is the purpose of a poly-T primer in the reverse transcription of mRNA?
To hybridize to the poly-A tail of the mRNA and initiate reverse transcription
Why is it challenging to express human proteins in bacteria?
All of the above
What is the purpose of protein tagging in recombinant protein expression?
To add a sequence of amino acids to the protein for easier purification
What is the primary purpose of DNA cloning?
Both a and c
What are restriction endonucleases?
Enzymes that recognize and cut DNA at specific sequences
What type of sequences are recognized by restriction endonucleases?
Palindromic sequences
How do restriction endonucleases cut DNA?
They can cut DNA in both blunt and staggered (off-center) manners
What is a vector in DNA cloning?
A carrier of the gene or DNA segment of interest
What are the products of a staggered (off-center) cut by a restriction endonuclease?
Sticky or cohesive ends
Which of the following protein tags allows for purification using beads with bound nickel ions?
Poly-His
What technique involves the transfer of separated proteins from a gel to a membrane for detection with antibodies?
Immunoblotting
Which of the following protein tags can be purified using a peptide corresponding to its amino acid sequence?
HA
What is the purpose of the FLAG tag in protein purification?
To allow detection using an antibody against the FLAG peptide
Which of the following protein tags is a fluorescent protein that can be detected by its fluorescence?
Green fluorescent proteins (GFP)
What technique allows the separation of proteins based on their size?
Gel electrophoresis (SDS-PAGE)
What technique involves the use of antibodies to purify a specific protein from a mixture?
Immunoprecipitation
What is the main purpose of DNA cloning?
All of the above
What is the key function of restriction endonucleases in DNA cloning?
To recognize and cut the phosphodiester bond at specific DNA sequences
What type of DNA ends are generated by a staggered (off-center) cut by a restriction endonuclease?
Sticky/cohesive ends
What is the defining characteristic of the DNA sequences recognized by restriction endonucleases?
They are palindromic sequences
What type of DNA ends are generated by a blunt cut by a restriction endonuclease?
Blunt ends
What is the primary advantage of using plasmids as cloning vectors in DNA cloning?
Plasmids can replicate independently of the host cell's chromosome
What is the main purpose of including a selectable marker gene, such as an antibiotic resistance gene, in a plasmid cloning vector?
To allow for the selection of cells that have successfully incorporated the recombinant plasmid
What is the role of DNA ligase in cloning?
Catalyzing the formation of phosphodiester bonds between DNA fragments
Why are plasmids considered good vectors for cloning?
They can replicate independently of the bacterial genome
What is the key feature that plasmid cloning vectors must possess?
Origin of replication allowing independent replication
What is the purpose of a selectable gene in a plasmid cloning vector?
To allow for selection of cells containing the vector
What is recombinant DNA technology part of?
Genetic engineering
Which statement best describes a clone?
Genetically identical individuals derived from a single source
What is the key step in creating recombinant DNA using vectors?
Joining a DNA fragment of interest into the vector
What is the role of DNA ligase in the creation of recombinant DNA?
Closing the plasmid
What is the primary function of a poly-T primer in reverse transcription?
Selecting human mRNA
Why are eukaryotic systems like yeast preferred for protein expression over bacteria?
To prevent post-translational modifications
What is the main advantage of using protein tagging in recombinant protein expression?
Facilitating protein purification
In the context of gene expression vectors, what do ShineDalgarno (SD) sequences function as?
Ribosomal binding sequences
What is the primary purpose of utilizing the same restriction endonuclease to cut both DNA fragments during cloning?
To create fragments with compatible sticky-ends
Why is plasmid used as a vector in DNA cloning?
To carry the DNA segment of interest
What is the primary function of a protein domain?
To act as a self-contained functional unit within the protein
What is the main purpose of using a GST-tag in recombinant protein production?
To purify the recombinant protein
What is the primary advantage of using a GFP-tag compared to a GST-tag in recombinant protein production?
GFP-tagged proteins can be detected without purification
Which of the following is a key characteristic of a protein domain?
It can fold independently from the rest of the protein
What is the primary purpose of producing recombinant proteins?
To generate large quantities of a desired protein
What is the main advantage of using plasmids as cloning vectors?
Plasmids can replicate independently within the host cell
What is the purpose of a promoter sequence in an expression vector?
To drive the expression of the recombinant gene
Which of the following is a required component of a plasmid cloning vector?
All of the above
What is the primary function of DNA ligase in the cloning process?
To join DNA fragments together
What is the purpose of including a selectable marker gene, such as an antibiotic resistance gene, in a plasmid cloning vector?
To enable the selection of host cells that have successfully taken up the recombinant plasmid
Explore the role of DNA ligase in joining DNA ends, as well as the concept of cloning and creating genetically identical populations. Understand how DNA fragments are joined and how cloning generates multiple copies of the same genetic material.
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