Microbial Recombination and Gene Transfer Questions :-
1. The plasmid-mediated properties is/are
A. fermentation of lactose
B. production of enterotoxin
C. resistance to antibiotics
D. all of these
Answer: D
2. In the extracellular medium, DNA-degrading enzymes would likely be to prevent transfer of DNA by
A. conjugal transfer by a self-transmissible plasmid
B. generalized phage transduction
C. natural transformation
D. none of the above
Answer: C
3. What is the term used for a segment of DNA with one or more genes in the centre and the two ends carrying inverted repeat sequences of nucleotides?
A. Plasmid
B. Transposon
C. Insertion sequence
D. None of these
Answer: B
4. The plasmids can be eliminated from a cell by the process known as
A. curing
B. breaking
C. fixing
D. expulsion
Answer: A
5. Recombination of virus genomes occurs
A. by transduction
B. by transription
C. simultaneous infection of a host cell by two viruses with homologous chromosomes
D. by transformation
Answer: C
6. The type of recombination that commonly occurs between a pair of homologous DNA sequences is,
A. mutagenic recombination
B. site-specific recombination
C. replicative recombination
D. general recombination
Answer: D
7. Which of the following statement describes plasmids?
A. Another name for a protoplast
B. A complex membrane structure that covers the chromosome of bacteria
C. Small, circular DNA molecules that can exist independently of chromosomes commonly found in bacteria
D. None of the above
Answer: C
8. In lysogeny,
A. a bacteriophage transfers bacterial DNA
B. bacteria take up double stranded DNA from the environment
C. DNA-degrading enzymes in the extracellular medium would stop the process
D. a bacteriophage genome is integrated into the bacterial genome
Answer: D
9. A microarray differs from a gene fusion in that, it
A. carries DNA segments from many different genes
B. is not constructed by cloning
C. gives direct measurement of mRNA level
D. all of the above
Answer: D
10. Who discovered transposons (jumping genes)?
A. Abelson
B. Harvey
C. McClintock
D. Griffith
Answer: C
11. Which type of plasmid can exist with or without being integrated into the host’s chromosome?
A. Medisome
B. Lisosome
C. Lysogen
D. Episome
Answer: D
12. The main difference between a self-transmissible and a mobilizable plasmid is that the self-transmissible plasmid
A. transfers both strands of the plasmid DNA
B. carries genes encoding the mating apparatus
C. transfers antibiotic resistance genes
D. usually has a transposon inserted into it
Answer: B
14. The transposase gene encodes an enzyme that facilitate
A. viral replication within a genome
B. general recombination
C. site-specific integration of transposable elements
D. none of the above
Answer: C
15. The term used for plasmids possessing both RTF and r determinants is
A. non self-transmissible plasmids
B. non conjugative plasmids
C. conjugative plasmids
D. none of the above
Answer: C
16. Diagnostic DNA probes have been developed for
A. Mycobacterium tuberculosis
B. Hepatitis B virus
C. Human immunodeficiency virus
D. all of the above
Answer: D
17. Which of the following statement(s) is/are true in regards to F+ x F- mating events?
A. DNA is transferred from F- to F+ cells
B. DNA is transferred from F+ to F- cells
C. No DNA is transferred because F- cells are unable to perform conjugation
D. No DNA is transferred because F+ cells are unable to perform conjugation
Answer: B
18. Which of the following type of recombination does not require homologous sequences and is important for the integration of viral genomes into bacterial chromosomes?
A. Mutagenic recombimation
B. Site-specific recombination
C. Replicative recombination
D. General recombination
Answer: B
19. What information can be generated by interrupted mating experiments?
A. Levels of DNA homology
B. Bacterial genome maps
C. DNA nucleotide sequences
D. Proteomics of the bacteria
Answer: B
20. Which of the following transport bacterial DNA to other bacteria via bacteriophages?
A. Conjugation
B. Transduction
C. Transformation
D. Translation
Answer: B
Microbial Recombination and Gene Transfer Objective type Questions with Answers
21. When composite transposons are formed
A. a small deletion occurs in the transposase gene of an IS element
B. a small deletion occurs in the transposase gene of an IS element and plasmid is integrated
C. an IS element integrates with another IS element with the help of a plasmid
D. two IS elements integrate into a chromosome with only a small distance separating them
Answer: D
22. Which of the following plamids do not possess information for self transfer to another cell?
A. Cryptic plasmids
B. Conjugative plasmids
C. Non-conjugative plasmids
D. None of these
Answer: C
23. The term used for acquisition of naked DNA from its environment and its incorporation in their genome by a bacterium is
A. transformation
B. lysogenic conversion
C. conjugation
D. transduction
Answer: A
24. What is term used for a bacterial cell that is able to take up naked DNA?
A. Complementary
B. Liable
C. Competent
D. Infected
Answer: C
25. Penicillin resistance in staphylococci is acquired due to
A. conjugation
B. mutation
C. transformation
D. transduction
Answer: D
26. The plasmid which makes the host more pathogenic is
A. F factors
B. Metabolic plasmid
C. Virulence plasmid
D. None of these
Answer: C
27. The expression of gene X (which has promoter Px) is to be monitored. A gene fusion construction for carrying this work will
A. have Px but not the rest of the X coding region
B. have the promoter of lacZ or some other reporter gene
C. allow to monitor the expression of all genes with a promoter similar in sequence to Px
D. give the same information as from a microarray
Answer: A
28. The transducing particles carry only specific portions of the bacterial genome in which of the following transduction?
A. Specialized transduction
B. General transduction
C. Abortive transduction
D. None of these
Answer: A
29. The correct term for the transfer of genetic material between bacteria in direct physical contact is
A. conjugation B. transformation
C. replication D. transduction
Answer: A
30. Plasmid that carries genes encoding enzymes, which degrade substances such as aromatic compounds, pesticides or sugar are
A. F factors
B. metabolic plasmid
C. virulence plasmid
D. none of these
Answer: B
31. R factors involved in plant-microbe interactions are
A. plant proteins
B. bacterial proteins
C. essential for transfer of DNA to plant cells
D. also called opines
Answer: A
32. Which of the following is used by microbial genetisists as a tool?
A. Bacteriophage
B. Plasmids
C. Transposable elements
D. All of these
Answer: D
33. Which of the following type of recombination does not require homologous sequences and is utilized by mobile genetic elements that move about chromosomes?
A. Mutagenic recombimation
B. Site-specific recombination
C. Replicative recombination
D. General recombination
Answer: C
34. Which of the following term describes the relationship between a virus and host where no new viral particles are produced and the viral genome is replicated along with host chromosome?
A. Lysogeny
B. Lysis
C. Transformation
D. Conjugation
Answer: A
35. Inverted repeat sequences at each end and a gene encoding transposase is contained in which of the following transposable element?
A. Composite transposon
B. Insertion element
C. Virus
D. Plasmid
Answer: B
36. F factor plasmids play a major role in
A. conjugation
B. replication
C. transduction
D. trasnscription
Answer: A
37. Which of the following genetic elements carry the genes required for integration into host chromosomes?
A. Replicon
B. Plasmids
C. Transposons
D. Tandons
Answer: C
38. The chromosomal genes, possessing fertility factor is known as
A. R factor
B. F prime factor
C. HFr
D. F factor
Answer: B
39. Which of the following statement can describe horizontal transfer?
A. The synthesis of protein in RNA
B. The transmission of genetic information from one independent, mature organism to another
C. The transmission of genetic information from parent to offspring
D. The synthesis of RNA from a DNA template
Answer: B