The enzyme used in the polymerase chain reaction is a :
(1) DNA dependent RNA polymerase
(2) RNA dependent DNA polymerase
(3) DNA dependent DNA polymerase
(4) RNA dependent RNA polymerase
Identify a character that is not desirable in a cloning vector:
1. an inactive promoter
2. an origin of replication site
3. selectable markers such as genes for antibiotic resistance
4. one or more unique restriction endonuclease sites
A cloning vector has two antibiotic resistance genes- for tetracycline and ampicillin. A foreign DNA
was inserted into the tetracycline gene. Non-recombinants would survive on the medium containing :
1. ampicillin but not tetracycline
2. tetracycline but not ampicillin
3. both tetracycline and ampicillin
4. neither tetracycline nor ampicillin
1. Separating the restricted DNA fragments on agarose gel.
2. Staining the separate DNA fragments with ethidium bromide
3. cutting out of the separated band of DNA from the agarose gel and extracting them from the gel piece.
4. constructing rDNA by joining the purified DNA fragments to the cloning vector.
When isolating the pure DNA from a bacterial cell, the cell should not be treated with:
A host cell normally does not take up a foreign DNA until it has been made competent to do so. This is because:
1. DNA is a hydrophilic molecule
2. DNA is a very large molecule
3. there are no receptors for DNA on the cell membrane
4. DNA is an inert molecule
Which statement regarding restriction endonucleases is NOT correct?
1. They recognize a specific base sequence in the DNA.
2. They are produced by bacterial cells as a primitive immune system.
3. They digest DNA by removing nucleotides from a free 3' end.
4. They often generate stick ends.
The technique not used for transformation of plant cells in recombinant procedures is:
2. Agrobacterium mediation
3. Use of viruses
In the screening process during rDNA experiments, clones that metabolize -gal turn:
Restriction enzymes are synthesized by:
1. Bacteria only
2. Yeast and bacteria only
3. Eukaryotic cells only
4. All kinds of cells
A gene, whose expression helps to identify transformed cells is known as
1. selectable marker
4. structural gene
Which of the following is not a component of downstream processing?
Which of the following restriction enzymes produces blunt ends?
(a) Sal I (b) Eco RV
(c) Xho (d) Hind III
The colonies of recombinant bacteria appear white in contrast to blue colonies of non-recombinant bacteria because of
(1) Non-recombinant bacteria containing -galactosidase
(2) Insertional inactivation of -galactosidase in non-recombinant bacteria
(3) Insertional inactivation of -galactosidase in recombinant bacteria
(4) Inactivation of glycosidase enzyme in recombinant bacteria
A single strand of nucleic acid tagged with a radioactive molecule is called
2. selectable marker
Electroporation procedure involves
1. fast passage of food through sieve pores in phloem elements with the help of electric stimulation
2. opening of stomatal pores during night by artificial light
3. making transient pores in the cell membrane to introduce gene constructs
4. purification of saline water with the help of a membrane system.
cDNA probes are copied from the messenger RNA molecules with the help of
1. restriction enzymes
2. reverse transcriptase
3. DNA polymerase
4. adenosine deaminase.
How are transformants selected from nontransformants?
1. Presence of more than one recognition site in the vector DNA.
2. Presence of alien DNA into the vector DNA results into insertional inactivation of selectable marker.
3. Antibiotic resistance gene gets inactivated due to insertion of alien DNA.
4. Both 2 and 3.
Plasmid vector in DNA recombinant technology means
1. a virus that transfers gene to bacteria
2. extra-chromosomal autonomously replicating circular DNA
3. sticky end of DNA
4. any fragment of DNA carrying desirable gene
Biolistic (gene gun) is suitable for
1. disarming pathogen vectors
2. transformation of plant cell
3. constructing recombinant DNA by joining with vectors
4. DNA fingerprinting
A mixture containing DNA fragments, a, b, c and d, with molecular weights of a+b = c, a > b and d>c, was subjected to agarose gel electrophoresis. The positions of these fragments from anode to cathode sides of the gel would be
(1) b, a, c, d
(2) a, b, c, d
(3) c, b, a, d
(4) b, a, d, c
pBR322, which is frequently used as a vector for cloning gene in E. coli is a/an
1. original bacterial plasmid
2. modified bacterial plasmid
3. viral genome
Go through the statements:
A. During the processing of the prohormone "proinsulin" into the mature "insulin", C-peptide is removed from proinsulin.
B. In hydridoma technology, B-cells are fused with myeloma cells.
C. Genetic engineering has been successfully used for producing transgenic mice for testing safety of polio vaccine before use in humans.
D. Some of the characteristics of Bt cotton are high yield and resistance to bollworms.
E. An improved variety of transgenic basmati rice gives high yield and is rich in vitamin A.
F. Gray biotechnology' is referred to industrial process.
G. The polymerase chain reaction is a technique that is used for in vivo replication of DNA.
How many statement(s) is wrong?
Molecular probes used for identification of recombinant clone carrying the desired DNA insert can be:
A. Denatured double stranded DNA probes
B. doubles stranded RNA probes
C. Protein probes
D. Single stranded DNA probes.
(1) A, B
(2) B, C
(3) A, D
(4) A, B, C, D
In 1960’s two enzymes were discovered in bacteria that were responsible for providing immunity against bacteriophages. One was Restriction Endonuclease and the other was
4. Terminal Transferase
E.coli is a commonly used host for gene cloning because
1. It is free from elements that interfere with replication and recombination of DNA
2. It is easy to transform
3. It supports replication of inserted DNA.
4. All of these
The names associated with construction of first Recombinant DNA are
a. Arber, Nathans, Smith
b. Annie Chang, Boyer, Berg, Cohen
c. Howard Temin, Brenner, Sharp
d. Tim Hunt, Hartwell, Nurse
The restriction enzymes most commonly used in rDNA technology are
1. Type 1 Restriction enzymes
2. Type II Restriction enzymes
3. Type III Restriction enzymes
4. Type IV Restriction enzymes
A protein is not expressed properly in a diseased tissue. To find out whether the defect is at the level of translation or post translational modifications which techniques would you use ?
a. Southern blotting and South Western blotting
b. Northern blotting and western blotting
c. Western blotting and Eastern blotting
d. Southern and Northern blotting
Insertional inactivation of a gene helps in
a. Identification of recombinant clones
b. Identification of deletion mutants
c. Identification of recombinant transformants
d. Elimination of suppression mutants
Look at the given hypothetical vector-
Suppose we cut the desired gene as well as the plasmid with the help of the Restriction enzyme EcoR I and ligate them. What would be true-
Insertional inactivation of the lac Z gene forms-
The visualization of the DNA bands on the gel can be done with the help of
If one needs to derive a cDNA of human insulin, which cells should be taken up for extraction?
Plasmids are good vectors for genetic engineering because
Why is a marker gene useful?
1. It shows you whether the gene being added, has been taken up or not.
2. It's a way of labelling which gene you want to modify.
3. It sticks with the striker gene.
4. It marks the position of r DNA
The introduction of genes into plant cells often makes use of
a. Disarmed Agrobacterium vectors
b. disarmed retroviral vectors
c. Ti plasmid of Agrobacterium
c. Ri plasmid of Agrobacterium
If you transform a cell with an alien piece of DNA only, What is the possibility?
1. This alien piece becomes a part of the host genome.
2. It doesn't become a part of the host's genome but keeps on replicating
3. The cloning of genes won't get affected in the absence of Origin of replication.
4. Multiple identical copies of an alien piece of DNA can be formed irrespective of its integration into the host's genome.
Restriction endonuclease cuts
1. At palindromic sequences for some enzymes not for all
2. After scanning and recognition of specific sequence in a DNA strand
3. Cuts the strand exactly at the centre
4. All of these
Arrange the following steps in order:
1) Restriction Digestion
2) Running Agarose gel
3) Elution of bands
4) Purification of DNA
In a DNA gel the fragment of 2kb and 3kb will be
1. 2kb nearer to cathode while 3kb nearer to anode
2. 2kb closer to wells while 3kb towards the opposite ends
3. 2kb closer to opposite end of gel while 3kb closer to well
4. 2kb away from cathode while 3kb towards anode