Vector Biology Multiple Choice Questions & Answers focuses on “Vectors and Cloning in Gram – Positive Bacteria – 4”.
1. What is nisin?
A. Inducer
B. Protein
A. Promoter
D. Suppressor
Answer: A
Clarification: Nisin is an inducer for the genes that are inserted in the vector or the host under the control of promoters nisA and nisF. The amount of expression obtained depends on the amount of nisin added.
2. The export system of E. coli is ________ to that in mammals.
A. Different
B. Similar
A. Larger
D. Smaller
Answer: A
Clarification: The export mechanism in low-GC bacteria resembles that of E. coli. However, there are differences in the signal peptides compared with those found in eukaryotes.
3. Two probe vectors were developed for the identification of secretion signals. These incorporated a gene from ___________
A. Streptococcus
B. Bacillus
A. Pseudomonas
D. Parasitoid
Answer: B
Clarification: Two probe vectors were developed for the identification of secretion signals. These vectors made use of a silent reporter gene encoding the mature amylase from Bacillus Licheniformis.
4. In probe vectors that identify secret signals, the reporter gene codes for___________
A. Lactose
B. Beta amylase
A. Alpha amylase
D. Amylase
Answer: C
Clarification: Two probe vectors were developed for the identification of secretion signals. These vectors made use of a silent reporter gene encoding the mature amylase from Bacillus Licheniformis.
5. Iodine used for the detection of secreted amylase ________ the bacteria.
A. Inactivates
B. Kills
A. Produces
D. Grows
Answer: B
Clarification: The disadvantage of the probe vector system is that the detection of secreted amylase involves flooding starch containing media with iodine and this kills the bacteria in the colonies.
6. Which media is used in the culture of probe detection vectors?
A. Starch
B. Glucose
A. Lactose
D. Pectin
Answer: A
Clarification: The disadvantage of the probe vector system is that the detection of secreted amylase involves flooding starch containing media with iodine and this kills the bacteria in the colonies.
7. To avoid killing of bacterial colonies in the iodine detection assay, which of the following techniques can be used?
A. Ligation
B. Dissection
A. Cloning
D. Replica Plating
Answer: D
Clarification: Flooding starch containing media with iodine and this kills the bacteria in the colonies, replica plates must be made before iodine addition.
8. The S. aureus-secreted nuclease is ______ amino acids long.
A. 100
B. 168
A. 208
D. 68
Answer: B
Clarification: An alternative probe system which uses the S. aureus-secreted nuclease as a reporter is a small 168 amino acids long, stable, monomeric enzyme that is devoid of cysteine residues and the enzymatic test is non-toxic to the bacterial colonies.
9. The S. aureus secreted nuclease is dimeric.
A. True
B. False
Answer: B
Clarification: S. aureus-secreted nuclease as a reporter is a small 168 amino acids long, stable, monomeric enzyme that is devoid of cysteine residues.
10. Inclusion of a synthetic polypeptide in probe vector system can ________________
A. Enhance secretion
B. Decrease secretion
A. Decrease size
D. Increase size