Vector Biology Puzzles focuses on “Vectors for Plants – 2”.
1. A two vector system contains a large normal vector and a small vector containing solely T-DNA fragment.
A. True
B. False
Answer: A
Clarification: A two vector system is basically constructed to surmount the problem of the big size of Ti plasmid. The basic principle is that no physical attachment of the plasmid with T-DNA is necessary.
2. The virulence region is contained in __________ of the binary vector system.
A. Large vector
B. Large vector along with specificity regions
A. Large vector along with restriction site
D. Small vector
Answer: B
Clarification: The virulence region and the host specificity region are contained in the larger plasmid and the T-DNA region along with a restriction site are contained in the smaller plasmid.
3. The unique restriction sites in a “binary vector system” are located in _________
A. T-DNA
B. Telomere sequence
A. Large plasmid
D. Small plasmid
Answer: D
Clarification: The unique restriction sites are located within the T-DNA region on the smaller plasmid which is about 20 kb in size. The sites are required for manipulations.
4. Which vector does the co-integration strategy use?
A. E.coli vector
B. Bacteriophage
A. Bacterial plasmid
D. Ti plasmid
Answer: A
Clarification: The co-integration strategy is adapted to surmount the problem of the huge size of the Ti plasmid. In this strategy, E.coli vector is used that contains a part of T-DNA.
5. In which region does the infection of wound happen in crown gall disease?
A. Leaf
B. Root
A. Stem
D. Leaf node
Answer: C
Clarification: The infection of the wound happens in the stem, the bacteria attack the plant at the wounded stem portion and the process of transfer proceeds.
6. What does disarming the vector mean?
A. Removing cancerous genes
B. Removing flanks of lacZ’
A. Mutating DNA
D. Removing T-DNA
Answer: A
Clarification: A mature plant regenerated from transformed cells will contain the cloned gene in every cell and will pass the cloned gene to its offspring.
7. Which parts of the T-DNA are involved in infection?
A. Interstitial sequence
B. 25bp sequence
A. Origin of replication
D. Opine genes
Answer: B
Clarification: The only parts of the T-DNA involved in infection are two 25 bp repeat sequences found at the left and right borders of the region integrated into the plant DNA.
8. What is Pbin19?
A. Binary vector
B. Hybrid vector
A. Plasmid vector
D. Ti plasmid vector
Answer: A
Clarification: PBIN19 is a disarmed cloning vector which is a binary vector. The left and right borders of this vector flank copy of lacZ’ gene.
9. What is the basic difference between Ri plasmid and Ti plasmid of Agrobacterium?
A. Disease caused
B. Parent molecule
A. Types of plants prone
D. Mode of infection
Answer: A
Clarification: Both Ri and Ti plasmid are present in the parent molecule of Agrobacterium Tumefaciens. The basic difference lies in the type of disease which the plasmid causes; due to its inherent capability of transferring a part of its own plasmid DNA to the genome of the plant.
10. Which disease is caused by Ri plasmid of Agrobacterium tumefaciens?
A. Crown gall disease
B. Hairy root disease
A. Carcinoma
D. Fungal infection
Answer: B
Clarification: The Ri plasmid of the soil bacterium species Agrobacterium Tumefaciens causes the hairy root disease in the attacked dicot plants. The underlying mechanism of this infection is the transferal of T-DNA of plasmid to the plant host genome.
11. Which of the following is a symptom of hairy root disease in plants?
A. Massive proliferation
B. Decreased proliferation
A. Cancerous outgrowth
D. Dwarfness in plants
Answer: A
Clarification: The Ri plasmid of Agrobacterium Rhizogenes causes a hairy root disease, typified by the massive proliferation of a highly branched root system.
12. Cloning genes in dicots are more difficult than cloning genes in monocots.
A. True
B. False
Answer: B
Clarification: Several factors have made it much more difficult to clone genes in monocots than in dicots such as tomato, tobacco, potato, peas.
13. Which of the following is an example of monocot?
A. Tobacco
B. Potato
A. Wheat
D. Peas
Answer: C
Clarification: Monocots include wheat, barley, rice, and maize, which are the most important crop plants and hence the most desirable targets for genetic engineering projects.
14. What is the technique of biolistics used for?
A. Regeneration of plants
B. Regeneration of plasmid
A. Introduction of DNA
D. Infection by Agrobacterium
Answer: C
Clarification: Biolistics are the techniques of bombardment with microprojectiles to introduce plasmid DNA directly into plant embryos.
15. Using the biolistics approach, which step is skipped in the process of cloning plants?
A. Use of Agrobacterium
B. Use of plasmids
A. Use of foreign gene
D. Use of embryos
Answer: A
Clarification: Biolistics circumvents the need to use Agrobacterium (Tumefaciens or Rhizogenes)as the means of transferring DNA into the plant cells.