Plasmids/Vectors Flashcards
What is a plasmid?
A plasmid is a small, circular, double-stranded DNA molecule found in bacteria that can replicate independently of chromosomal DNA and often carries beneficial genes.
What is a vector in genetic engineering?
A vector is an artificially made DNA molecule that facilitates the incorporation of foreign DNA for manipulation and replication.
What are restriction endonucleases?
Enzymes that cleave DNA molecules at specific recognition sequences, producing fragments useful for genetic engineering.
How do bacterial cells take up plasmids?
Through transformation, which can be induced by heat shock or electroporation.
What is recombinant DNA technology?
A method used to insert foreign genes into plasmids, allowing bacteria to express desired proteins.
Plasmids are used as cloning vectors in
biotechnology.
Restriction enzymes cut DNA at specific sites, allowing
gene insertion.
The origin of replication (OR) enables
plasmid self-replication.
The lacZ gene is used in
blue/white screening for successful gene cloning.
Recombinant insulin was first commercially produced using
genetically modified E. coli.
Plasmids always integrate into the bacterial genome.
False – Most plasmids replicate independently.
Electroporation uses an electric current to increase DNA uptake.
True.
All restriction enzymes cut DNA at random locations.
False – They cut at specific recognition sequences.
Cloning vectors can carry genes for antibiotic resistance.
True.
The enzyme responsible for linking DNA fragments together is called __________.
A: DNA ligase.
A bacterium capable of taking up foreign DNA is said to be __________.
A: Competent.
The method of screening recombinant bacteria using the lacZ gene is called __________ screening.
A: Blue/white.
The two common methods for inducing bacterial transformation are __________ and __________.
A: Heat shock, electroporation.
What is the function of a multiple cloning site in a plasmid?
A) Protect the bacterial chromosome
B) Provide multiple restriction sites for gene insertion
C) Prevent transformation
D) Enhance bacterial metabolism
A: B) Provide multiple restriction sites for gene insertion.
Which of the following is NOT a feature of plasmids used in genetic engineering?
A) Origin of replication
B) Antibiotic resistance gene
C) Mitochondrial DNA
D) Restriction enzyme sites
A: C) Mitochondrial DNA.
What is a common bacterial host for cloning plasmids?
A) Staphylococcus aureus
B) Escherichia coli
C) Saccharomyces cerevisiae
D) Mycobacterium tuberculosis
A: B) Escherichia coli.
What is a key step in recombinant insulin production?
A) Inserting the human insulin gene into a bacterial plasmid
B) Using bacteria to synthesize viral proteins
C) Growing human cells in a bioreactor
D) Producing insulin in fungal spores
A: A) Inserting the human insulin gene into a bacterial plasmid.
A researcher uses restriction enzymes to cut a plasmid and insert a foreign gene. What enzyme is needed to join the fragments?
A: DNA ligase.
A scientist introduces a plasmid containing an antibiotic resistance gene into bacteria. How can they confirm successful transformation?
A: Grow bacteria on antibiotic-containing media to select for transformed cells.
