1. You have cloned a human gene along with its promoter and ribosome-binding site in a bacterial cloning vector and then introduced the recombinant plasmid into a bacterial host cell that supports the replication and segregation of the cloning vector. Unfortunately, even though you know the whole human gene sequence is present (by DNA hybridization); you cannot get expression of the gene. Which of the following is NOT a reason why there is no expression?
A. The vector cannot replicate
B. The human promoter is not recognized by the bacterial host cell
C. The ribosome-binding site is not recognized by the bacterial host cell
D. The human gene lacks introns, so it is not transcribed by the host bacterium
2. Restriction endonucleases are:
A. sequence-specific
B. able to recognize any 4-, 6-, or 8-base pair sequence
C. always able to produce single stranded tails
D. only able to cleave bacterial DNA
3. Which of the following is NOT a required characteristic of cloning vectors?
A. Genes for replication of vector DNA and segregation to progeny cells
B. Genes for selection of cells carrying the vector (e.g., antibiotic-resistance)
C. DNA sequence for the introduction of foreign DNA where the integrated DNA does not disable the vector
D. None of the above
4. A poly (T) primer is used to produce cDNA from mammalian mRNA. Which of the following would be used to produce cDNA from bacterial mRNA?
A. A poly (T) primer
B. A random DNA sequence primer
C. A poly (A) primer
D. A poly (GC) primer
1. You have cloned a human gene along with its promoter and ribosome-binding site in a bacterial cloning vector and then introduced the recombinant plasmid into a bacterial host cell that supports the replication and segregation of the cloning vector. Unfortunately, even though you know the whole human gene sequence is present (by DNA hybridization); you cannot get expression of the gene. Which of the following is NOT a reason why there is no expression?
A. The vector cannot replicate
B. The human promoter is not recognized by the bacterial host cell
C. The ribosome-binding site is not recognized by the bacterial host cell
D. The human gene lacks introns, so it is not transcribed by the host bacterium
2. Restriction endonucleases are:
A. sequence-specific
B. able to recognize any 4-, 6-, or 8-base pair sequence
C. always able to produce single stranded tails
D. only able to cleave bacterial DNA
3. Which of the following is NOT a required characteristic of cloning vectors?
A. Genes for replication of vector DNA and segregation to progeny cells
B. Genes for selection of cells carrying the vector (e.g., antibiotic-resistance)
C. DNA sequence for the introduction of foreign DNA where the integrated DNA does not disable the vector
D. None of the above
4. A poly (T) primer is used to produce cDNA from mammalian mRNA. Which of the following would be used to produce cDNA from bacterial mRNA?
A. A poly (T) primer
B. A random DNA sequence primer
C. A poly (A) primer
D. A poly (GC) primer
