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CBSE Questions for Class 12 Medical Biology Biotechnology: Principles And Processes Quiz 4 - MCQExams.com
CBSE
Class 12 Medical Biology
Biotechnology: Principles And Processes
Quiz 4
Restriction enzymes were used to cleave a section of DNA into four fragments. These fragments were 400, 600, 1800, and 3000 base pairs long.
Which gel electrophoresis well in the image most likely represents these fragments?
Note: The wells are drawn as boxes at the bottom of the diagram.
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Well A
0%
Well B
0%
Well C
0%
Well D
Explanation
DNA fragments when subjected to gel electrophoresis move towards anode or the positive electrode. The speed and distance of movement depends upon the length of the DNA fragment that is also the number of base pairs that make the fragment. So, the shorter fragments will travel faster and farther from the wells as compared to the larger fragments. Based on the number of base pairs the image of well A represents the distribution
So, the correct answer is '
Well A'
Which vector can clone a small fragment of DNA?
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Bacterial artificial chromosome
0%
Yeast artificial chromosome
0%
Plasmid
0%
Cosmid
Explanation
Plasmids are autonomously replicating circular extra-chromosomal DNA.
They are the standard cloning vectors and the ones most commonly used.
Most general plasmids may be used to clone DNA insert of up to 15 kb in size.
One of the earliest commonly used cloning vectors is the pBR322 plasmid.
So, the correct answer is option C.
Restriction endonucleases will make two types of cuts, those that result in blunt ends (A) and ends with overhangs of one strand (B).
Based on the chemical characteristics of the fragment ends, predict which type of digest is more likely to happen?
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The blunt fragments are more likely because the re-annealing process is a seamless connection.
0%
The blunt fragments are more likely, because of complementarity of the adjoining fragments
0%
The overhang ends are more likely because the overhangs fit like two puzzle pieces.
0%
The overhang ends are more likely because of base complementarity leading to optimal hydrogen bonding.
Explanation
The ligation of blunt ends is more difficult to occur and requires high concentration of blunt end fragments that are to be ligated. High concentration of enzyme ligase, low concentration of ATP and PEG for ligation to occur. However, this can be easily achieved if the restriction enzymes cut the DNA with staggering ends, the ligation occurs naturally with other DNA fragments with complementary base pairs.Therefore, of the two types of cuts by different types of restriction enzymes, the sticky end cuts are more preferable over blunt ends.
So, the correct answer is '
The overhang ends are more likely because of base complementarity leading to optimal hydrogen bonding'
The restriction enzyme, Eco RI, recognizes and cuts the sequence below.
Based on the cut pattern, what types of bonds are cleaved by the action of the enzyme?
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Covalent bonds between the sugar and nitrogenous base.
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Covalent bonds within the nitrogenous base.
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Covalent bonds between the sugar and phosphate groups.
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Hydrogen bonds between the sugar and phosphate.
Explanation
Restriction enzymes cleave the covalent phosphodiester between sugar and phosphate, hydrogen bonds that hold together two complementary nitrogen bases are weak bonds that do not require any enzyme mediated separation.
So, the correct answer is '
Covalent bonds between the sugar and phosphate groups'
Which one of the following statements is wrong with respect to the separation of DNA fragments on electrophoresis?
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The DNA fragments move towards anode under electric field through the matrix.
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The commonly used matrix is agarose gel.
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The DNA fragments resolve according to their size.
0%
None of the above.
Explanation
Agarose gel electrophoresis is mainly used to separate the DNA molecule on the agarose gel matrix. The negatively charged molecules of DNA are loaded as a sample on the deeply carved wells on the gel. The loaded sample is induced by a strong electric field which leads to the separation of DNA on the basis of mass and the charge on the DNA. As all the DNA molecules have the same charge so they get aligned on the basis of mass. The smaller DNA molecules moves faster and get aligned at the top with the larger segment at the bottom. So, the correct answer is option D.
Plasmid DNA isolated from a bacterial lysate was digested with restriction enzymes X and Y. The preparations were then electrophoresed on agarose gels producing the DNA fragment patterns shown in the figure.
For the purpose of estimating fragment length, sizing markers were run simultaneously (lane 1). Other preps were: Uncut DNA (lane 2), enzyme X-treated DNA (lane 3), enzyme-Y treated DNA (lane 4), DNA treated with enzymes X and Y simultaneously (lane 5).
Based on the fragment patterns of the panel of digests, identify the most likely restriction map.
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0%
0%
0%
0%
Explanation
Plasmid DNA treated with both the restriction enzymes, X and Y simultaneously two fragments correspond Y at 3000 bp and 1000 bp, while a fragment at 2000 bp has two fragments of 2000 bp cut by enzymes X and Y
So, the correct answer is 'option A'
Which one of the following statements is not correct about a plasmid?
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It has a circular DNA
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It has antibiotic resistant gene
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It has the ability of autonomous replication
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It's DNA is as long as chromosomal DNA
Explanation
The plasmid is a single circular extrachromosomal DNA which carries antibiotic-resistant gene and origin of replication i.e., the ability of autonomous replication and its size is smaller than chromosomal DNA. These characters of plasmid make it an ideal vector for recombinant DNA technology. Thus, the correct answer is option D.
A gel electrophoresis was run to show the fragments produced by restriction digests with different restriction enzymes. The MWR lane indicates the molecular weight ruler.
Construct a restriction map of the double digest of the plasmid.
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0%
0%
0%
0%
Explanation
The plasmid was digested using restriction enzymes EcoRI and HaeIII which is called double digest. The gel electrophoresis of the plasmid after subjecting it to restriction enzymes, three fragment are observed on the gel plate.
So, the correct answer is 'option D'
ECORI cleaves the DNA strands to produce
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Blunt ends
0%
Sticky ends
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Satellite ends
0%
Ori replication end
Explanation
Sticky ends are formed when the restriction enzymes cut the DNA molecule at such a position that it leaves an overhanging stretch of the nitrogenous base which can pair with the complementary base pairs.
EcoRI cut through the DNA strands at nucleotides that overhangs at the end.
This overhanging nucleotide strand is called a sticky end because it can easily bond with complementary DNA fragments. So, the correct answer is option B.
Direct gene transfer was first used in
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Potato plant
0%
Tobacco plant
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Tomato plant
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None of the above
Explanation
The method in which there is no involvement of the vector in the gene transfer is known as the direct gene transfer method. Different chemicals like PEG and calcium phosphate are used to make the cells competent which can take up the recombinant DNA. The method of direct gene transfer was first applied to the tobacco plant. An antibiotic resistance gene was transferred in the plant cell.
Thus, the correct answer is option B.
Match the entries in Column I with those of Column II and choose the correct answer.
Column - I
Column - II
(A)
Restriction endonucleases
(P)
Kohler and Milstein
(B)
Polymerase chain reaction
(Q)
Alec Jeffreys
(C)
DNA fingerprinting
(R)
Arber
(D)
Monoclonal antibodies
(S)
Karry Mullis
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$$(A) - (R), (B) - (S), (C) - (Q), (D) - (P)$$
0%
$$(A) - (R), (B) - (Q), (C) - (S), (D) - (P)$$
0%
$$(A) - (Q), (B) - (R), (C) - (S), (D) - (P)$$
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$$(A) - (Q), (B) - (S), (C) - (R), (D) - (Q)$$
Explanation
Restriction enzymes are enzymes that cut a DNA molecule at a particular place. Its mode of action was first demonstrated by Werner Arber in 1906.
Polymerase chain reaction is used for amplification of DNA which was first demonstrated by Kary Mullis.
DNA fingerprinting is used to establish a link between biological evidence and a suspect in a criminal investigation. It was first developed by Alec Jeffreys.
Monoclonal antibodies are the specific antibodies produced by myeloma cells and spleen cells immunised by a specific antigen. It was first produced by Kohler and Milstein.
So, the correct answer is option A.
During gene cloning, the enzyme used to join the insert DNA with the plasmid vector is
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DNA ligase
0%
Restriction endonuclease
0%
Alkaline phosphatase
0%
Exonuclease
Explanation
The process of cloning starts with the cleavage of foreign DNA by a restriction endonuclease enzyme.
The cleaved DNA is ligated to the plasmid vector for its transformation into the host cell.
The DNA is ligated by DNA ligase by the formation of phosphodiester bonds.
So, the correct answer is option A.
Transfer of genetic material into a bacterial cell through a viral vector is known as
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0%
Transformation
0%
Transduction
0%
Transfection
0%
Translation
Explanation
The process of transfer of DNA from one bacterium to another with the help of vector, that is, the virus is called transduction. Transduction does not require physical contact between the cells for donating the DNA.
In the transduction process, bacteriophage DNA gets incorporated into the bacterial genome and replicates with the bacterial genome.
Thus, the correct answer is option B.
Bacterial resistance to antibiotics is a genetic trait, it is normally carried by the
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Centromere
0%
Plasmid
0%
Chromosome
0%
Intron
Explanation
The plasmid is an extrachromosomal material in bacteria and used as a carrier DNA because it has an antibiotic resistance gene which makes it easy to isolate the transformed cell with the desired insert in it.
The plasmid genes confer resistance to one or more antibiotics. They have the ability to transfer by conjugation between bacterial species and are significantly involved in the emergence and dissemination of multiple drug resistance associated with bacterial infections in humans.
The transfer of a copy of plasmid from resistant to sensitive bacteria provides the capability of drug resistance.
Thus, the correct answer is option B.
The enzymes which are absolutely necessary for recombinant DNA technology are :
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Restriction endonucleases and topoisomerases
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Endonucleases and polymerases
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Restriction endonucleases and Ligases
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Peptidases and Ligases
Explanation
Recombinant DNA technology is the method which involves cutting and joining of different DNA fragments.
This rDNA is then inserted into the host and allowed to produce the desired product.
The restriction enzymes are the enzymes which cleaves the DNA at specific recognition sites.
This helps in the production of fragments and desired genes. The enzyme ligases are used to join or ligate the fragments.
These are two important enzymes with respect to rDNA technology.
Thus, the correct answer is option C.
In which of the following method, foreign DNA is directly injected into a cell?
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Direct gene transfer
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Liposome-mediated gene transfer
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Microinjection
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All of the above
Explanation
Direct gene transfer includes
the transfer
of the foreign gene of interest into the host plant cell without the help of a vector.
Liposome-mediated gene transfer includes the transfer of foreign DNA with the help of liposomes.
Liposomes are spheres of lipids that can be used to transport molecules into the cells.
Microinjection includes direct injection of DNA is into plant protoplasts or cells using a fine-tipped glass needle or micropipette.
Thus, the correct answer is option C.
Identify the desirable characteristics for a plasmid used in rDNA technology from the following.
$$A$$. Ability to multiply and express outside the host in a bioreactor.
$$B$$. A highly active promoter.
$$C$$. A site at which replication can be initiated.
$$D$$. One or more identifiable marker genes.
$$E$$. One or more unique restriction sites.
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A, C, and E only
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B, C, and E only
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A, C, D, and E only
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B, C, D, and E only
Explanation
The plasmid is the small circular DNA. These are extra chromosomal DNA which can replicate individually. The plasmid is inserted with a desired gene and then introduced in the host cell. The characters which makes plasmid suitable to be used in rDNA technology and genetic engineering techniques:
There should be an active promoter site and the origin of replication site called as Ori site.
These regions will allow the plasmid to replicate in the host.
There should be marker genes which can be used to identify the recombinants.
In order to insert the desired gene, there should be presence of restriction sites.
Thus, the correct answer is option D.
Electroporation is also known as
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Electropermeabilization
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Oxidative phosphorylation
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Transfection
0%
None of the above
Explanation
Electroporation is also called as electropermeabilization. It is a technique in which an electrical field is applied to cells so as to increase the permeability of the cell membrane, allowing DNA to enter into the cell. In molecular biology, the process of electroporation is often used to transform bacteria, yeast or plant protoplasts. Electroporation is also highly efficient for the introduction of foreign genes into tissue culture cells.
Thus, the correct answer is option A.
In recombinant DNA technique, the term vector refers to
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Donor DNA, is identified and picked up through electrophoresis
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Plasmid, transfers DNA into living cell
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Collection of entire genome in form of plasmid
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Enzyme, cuts the DNA at specific sites
Explanation
Vector is a DNA molecule used as a vehicle to artificially carry foreign genetic material into another cell, where it can be replicated and expressed. A
recombinant DNA technology
is a technique of transferring a desired gene into another and combining them for obtaining a sequence that is not found in the genome.
The four major types of vectors are plasmids, viral vectors (bacteriophages), cosmids and artificial chromosomes.
Thus, the correct answer is option B.
What is the name for mobile genetic elements?
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Plasmids
0%
Pili
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Bar body
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Transposons
Explanation
Transposons are mobile genetic elements.
These are segments of DNA that can move around to different positions in the genome of a single cell.
It is a segment of DNA that is capable of moving into a new position within the same or another chromosome or plasmid. It is also called the jumping genes.
So, the correct answer is option D.
In nomenclature of REN (restriction endo - nuclease) $$Hind$$ $$III$$, III stands for
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Genus name
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Species name
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Order of discovery
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Strain of the organism
Restriction endonucleases are enzymes that are used by biotechnologists to
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Cut DNA at specific base sequences
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Join fragments of DNA
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Digest DNA from the 3' end
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Digest DNA from the 5' end
Explanation
The restriction endonucleases are the enzymes which cleave the DNA at specific recognition sites present in the DNA sequences. This helps in the production of fragments and desired genes. This enzyme is widely used with respect to the recombinant DNA technology.
Thus, the correct answer is option A.
The .......... enzyme is used to cut DNA at specific point.
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DNA polymerase
0%
Alkaline phosphatase
0%
Restriction endonuclease
0%
DNA ligase
Explanation
Restriction endonucleases are enzymes which scan the DNA molecule for a particular nucleotide sequence. These are called recognition sequences. Once the endonuclease finds this sequence it halts and cuts the strand. Thus the correct answer is option C.
When genomic DNA is fragmented and cloned, the screening of the desired gene is done by using ?
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Plasmid DNA
0%
DNA probes
0%
Southern blotting
0%
PCR technique
Explanation
DNA probes are short DNA sequences that are used to identify the desired gene, out of a large number of DNA fragments, carrying the complementary nucleotide sequence. PCR - technique amplify the DNA samples. The DNA fragments from gel electrophoresis are transferred from the gel to the surface of the nylon via southern blotting. Plasmid DNA serves as vector for the gene cloning. So, the correct answer is option B.
Which one of the following organism's plasmid was used successfully for the first time as a vector by Stanley Cohen and Herbert Boyer?
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Salmonella typhimurium
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Streptococcus pneumoniae
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Staphylococcus aureus
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Rhizobium leguminosarum
Explanation
S. Cohen and H. Boyer constructed the first recombinant DNA using antibiotic resistance genes present on the plasmid of drug resistance strains of
E. coli
. This gene was linked to the native plasmid of
Salmonella typhimurium.
So, the correct answer is option A.
How many bands are seen when immunoglobulin G molecules analysed on a sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS_PAGE) under reducing conditions ?
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0%
6
0%
1
0%
2
0%
4
Explanation
Immunoglobulins are the antibody molecule which are composed of four polypeptide chains. There are two light and two heavy chains. When the immunoglobulin G (IgG) molecules are analyzed on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under the reducing conditions, there are two bands formed one of the light chain and one of the heavy chain.
Thus, the correct answer is option C.
Alec Jeffreys used .......... as genetic marker.
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Humulin
0%
Radioactive probe
0%
RFLP
0%
VNTR
Explanation
The technique of isolating and sequencing the DNA is called DNA fingerprinting. This technique was developed by Alec Jeffrey in 1984. Generally, a small amount of DNA is obtained from the samples. PCR technique is used to amplify the DNA molecules present in a small sample in order to obtain a large amount of DNA sequence for the test. This is followed by restriction fragment length polymorphism (RFLP). RFLP analysis is used to identify the repeated sequences by detecting a specific sequence pattern to the Variable Number Tandem Repeats which becomes that individual's DNA profile also called as genetic markers.
Thus the correct answer is option D.
A scientist has cloned an $$8$$ $$Kb$$ fragment of a mouse gene into the Eco RI site of a vector of $$6$$ $$Kb$$ size. The cloned DNA has no other Eco RI site within. Digestions of the cloned DNA is shown below.
Which one of the following sets of DNA fragments generated by digestion with both Eco RI and Bam HI as shown in (iii) is from the gene?
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$$1$$ $$Kb$$ and $$5.5$$ $$Kb$$
0%
$$1$$ $$Kb$$ and $$2.5$$ $$Kb$$
0%
$$1$$ $$Kb$$ and $$3$$ $$Kb$$
0%
$$1$$ $$Kb$$ and $$3.5$$ $$Kb$$
Explanation
The
4Kb fragment is the same in both the BamHI digest and the double digest having Eco RI and BAMH1. The 6Kb sequence is made from 3.5 and 2.5Kb. Since the cloned DNA has no Eco RI site within it, the Eco RI has to be inserted at the 8 Kb fragment. Hence the 8Kb sequence is fragmented as 1Kb, 4 Kb and 3Kb. Thus the correct answer is option C.
How many linear DNA fragments will be produced when a circular plasmid is digested with a restriction enzyme having $$3$$ sites?
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$$4$$
0%
$$5$$
0%
$$3$$
0%
$$2$$
Explanation
A circular plasmid can be cleaved using restriction enzymes. These restriction enzymes cleave the plasmid at specific sites. On cleaving a circular DNA 3 fragments of DNA will be obtained as there are 3 recognition sites for restriction enzyme. Thus, the correct answer is option C.
Which one of the following techniques is used for the detection of proteins ?
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Nothern blotting
0%
Western blotting
0%
Southern blotting
0%
In-situ hybridization
Explanation
Western blotting is the technique used for the detection of proteins. Separation of proteins is done using gel
electrophoresis
that takes place based on their molecular weight. These proteins are then transferred to a membrane in which a band is formed for every protein. In the final step, the membrane is incubated with labelled antibodies. The antibody is chosen such that it binds to the protein of interest. Thus, the correct answer is option B.
In plasmid pBR 322, 'BR' stands for
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Baculovirus and Retrovirus
0%
Boyer and Reed
0%
Bolivar and Rodrigues
0%
Bacillus and Rhizobium
Explanation
In plasmid pBR 322, 'BR' stands for Bolivar and Rodriguez, the scientists who constructed the plasmid. The letter 'p' stands for the plasmid.
So, the correct answer is option C.
Consider the linear double-stranded DNA shown below. The restriction enzyme sites and the lengths demarcated are shown. This DNA is completely digested with both EcoRI and BamHI restriction enzymes. If the product is analyzed by gel electrophoresis, how many distinct bands would be observed?
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0%
5
0%
2
0%
3
0%
4
Explanation
There are two sites for EcoRI and one site for BamHI. When the given DNA segment is cleaved with the two enzymes EcoRI and BamHI, the bands formed are bands of 1 kb, 5 kb and two bands of 3kb. When these DNA segments are analyzed by gel electrophoresis, there are 3 bands obtained on the basis of different sizes of the fragments.
Thus, the correct answer is option C.
In the nomenclature of enzyme restriction endonuclease, the roman numeral indicates
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0%
Number of times it is used
0%
The order of discovery from source
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Number of cuts of DNA
0%
Number of recombinants formed
The term 'southern blotting' refers to
Report Question
0%
Transfer of DNA fragments from in vitro cellulose membrane to electrophoresis gel
0%
Attachment of probes to DNA fragments
0%
Transfer of DNA fragments from electrophoresis gel to nitrocellulose sheet
0%
Comparison of DNA fragments from two sources
Explanation
Southern blotting is used to detect specific DNA sequence in a given sample of DNA. The first step in a Southern blot is to prepare the DNA mixture by breaking it into small fragments using a restriction enzyme. The mixture of DNA fragments is then separated according to size by gel electrophoresis. Then the double-stranded pieces of DNA are denatured into single strands within the gel. Next, the DNA is transferred from the gel onto a blotting membrane called the nitrocellulose membrane. The DNA is labeled using radioactive probes that can be detected by autoradiography.
Thus the correct answer is option C.
Relatively small DNA molecules of plasmids can be identified
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0%
Due to similarity to original nuclear DNA molecule
0%
By their restriction fragment patterns
0%
By the size of bacterial cell
0%
By their circular shape
Explanation
Restriction fragment length polymorphism (RFLP) is a technique used to analyze unique patterns in DNA fragments in order to genetically differentiate between organisms.
Restriction endonucleases cut the plasmid DNA into short segments. These restriction fragments produced during DNA fragmentation are analyzed using gel electrophoresis.
Hence the
small DNA molecules of plasmids can be identified by their restriction fragment patterns.
Thus the correct answer is option B.
Electric field is used in separating chemicals in which method?
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Ion exchange chromatography
0%
Electrophoresis
0%
Thin layer chromatography
0%
Column chromatography
Explanation
B. Electrophoresis
Solution : Electric field is used in separating chemicals in electrophoresis where the components get separated based on their charge. and migrate towards the respective positive and negative electrodes.
So the correct answer is "Electrophoresis".
A method which uses paper or film with different electric poles at the two ends and is used for separation of charged particles is called
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0%
Electrolysis
0%
Electrophoresis
0%
Electroplating
0%
Thin layer chromatography
Explanation
B. Electrophoresis
Solution : The method where a film or paper is used to separate charged particles with two different electric poles at two ends is called electrophoresis. The method is done to separate the DNA molecules based on their charge and mass.
So the correct answer is " Elctrophoresis"
What is the criterion for DNA fragments movement on agarose gel during gel electrophoresis?
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Negatively charged fragments do not move
0%
The larger the fragment size, the farther it moves
0%
The smaller the fragment size, the farther it moves
0%
Positively charged fragments move to farther end
Explanation
(A) Correct answer (C)
(B) Explanation of correct answer:
Gel electrophoresis is used to segregate DNA fragments according to mass and size.
DNA is negatively charged and it will travel towards the positive electrode. Hence separation will be on the size of the fragments.
The smaller DNA molecules move faster and farthest followed by the larger ones.
The DNA fragments separated on an agarose gel can be visualized after staining with
Report Question
0%
Ethidium bromide
0%
Bromophenol blue
0%
Acetocarmine
0%
Aniline blue
Explanation
Agarose gel electrophoresis is used to segregate DNA fragments according to the mass and size.
Ethidium bromide is the fluorescent stain used
in this technique.
Ethidium bromide, when exposed to ultraviolet light, produces a fluorescent effect. Hence the DNA tagged by it can be traced quickly on the transparent gel.
Thus the correct answer is option A.
The genetic material of $$M_{13}$$ bacteriophage is
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0%
ds DNA
0%
ds RNA
0%
ss RNA
0%
ss DNA
Explanation
M
13
M13
bacteriophage is a virus containing circular single stranded DNA enclosed by a thin flexible protein tube. It is a filamentous phage that infects
E.coli
and produces new virions without lysing the host cell.
Thus, the correct answer is option D.
The base material that is widely used in electrophoresis is
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Agar
0%
Agarose.
0%
Agar-Agar
0%
None of the above
Explanation
B. is the answer
The material on which gel electrophoresis is done is mainly agarose. Agarose is the purified form of agar that is extracted from a sea-weed. Agarose does not show any hindrance while the samples run on the gel made up of agarose.
Which one of the following is a recognition site for restriction enzyme Bam HI?
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$$5'$$- GAATTC- $$3'3'$$- CTTAAG-$$5'$$
0%
$$5'$$- GGATCC- $$3'5'$$- CCATGG-$$3'$$
0%
$$5'$$- GGATCC-$$3'3'$$-CCTAGG-$$5'$$
0%
$$5'$$-GAATTC-$$3'5'$$-GTTAAC-$$3'$$
Explanation
Bam H1 is a type of restriction endonuclease enzyme that binds to the nonspecific DNA and recognizes the sequence of 6bp. It produces sticky end when making a nick at the base of guanosine.
Which one of the following enzyme cuts the DNA within the specific positions?
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Exonuclease
0%
Alkaline phosphatase
0%
Restriction endonuclease
0%
Reverse transcriptase
Explanation
Restriction endonucleases recognize specific sequences in the DNA and cut the DNA into fragments.
Each restriction endonuclease has a specific restriction site; cuts at specific sites produce uniform DNA fragments with sticky or blunts ends that are easily ligated with other DNA strands.
Hence, the correct answer is C.
What is the source of Ti plasmid used in genetic engineering?
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Escherichia coli
0%
Bacillus thuringiensis
0%
Agrobacterium thizogenes
0%
Agrobacterium tumefaciens
Explanation
Agrobacterium tumefaciens
is a Gram-negative bacterium which is rod-shaped and motile. The bacterium causes crown gall disease (tumour like growth in the crown region) in many dicots. A plasmid called Ti plasmid (tumour inducing plasmid) is present in tumour cells of
Agrobacterium tumefaciens
, which integrates it tumour causing gene (tRNA) Into the host genome resulting into gall formation in crown region, Ti plasmid Is extensively used in genetic engineering and currently is being used in genetic modification of plants like cotton, tomatoes, potato, rice, maize, etc.
Which technique is used in the detection of a particular protein?
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0%
Buoyant density centrifugation
0%
Density gradient centrifugation
0%
Western blotting
0%
Both B and C
Explanation
Western blotting is one of the most important
techniques used
in
protein detection
and identification. By using this
technique
, researchers can accurately
detect
the presence and isolate a
particular protein
of interest from a mixture of
proteins
present in any biological sample.
so, the correct answer is '
Western blotting'
Electrophoresis is employed for
Report Question
0%
Separating cell components.
0%
Separating charged particles.
0%
Reverse osmosis.
0%
In vitro storage of cell components.
Explanation
B. Separating charged particles
Solution : Electrophoresis is the process where charged particles are separated by using an electric field. The particles move towards the respective opposite electrodes and are separated.
So the correct answer is "
Separating charged particles"
Agarose gel used to separate ___________.
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Carbohydrates
0%
Fats
0%
Proteins
0%
Both A and B
Explanation
C. Proteins
Solution : Agarose gel is a common base medium used in the separation of proteins and DNA using electric current. The gel is used to separate the proteins based on their charge and mass.
So the correct answer is "Proteins".
PCR is related with
Report Question
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DNA cloning
0%
Amplification of DNA
0%
DNA selective replication
0%
Amplification of RNA
Explanation
Polymerase chain reaction is a technique which is mainly used to amplify a DNA segment. It was given by Kary Mullis. The sample DNA strand is denatured by heating at the temperature of 95$$^o$$C. Each strand act as the template for the new strand. The primers are annealed at 55 $$^o$$C to all the template. In the third step, the temperature is raised to about 72$$^o$$C and the DNA polymerase also known as Taq polymerase begins adding nucleotides onto the ends of the annealed primers.
The key ingredients of polymerase chain reaction are Taq polymerase which is DNA polymerase enzyme that makes new DNA isolated from bacterium
Thermus acquaticus
.
So, the correct answer is option A.
Restriction endonucleases were discovered by
Report Question
0%
Arber et al
0%
Monod et al
0%
Cech et al
0%
Altman et al
Explanation
Restriction endonucleases were discovered by Arber et al. They are used in genetic engineering for gene manipulation.
It cuts DNA base pairs at specific sites. They cut the base pairs within the molecule so they are named as an endonuclease. 3000 restriction enzyme has been discovered till now.
They are known as molecular scissors as they are used to cut a single gene from a larger piece of DNA.
The restriction enzyme Eco RI, Bam II, and Hind Ill are used in recombinant DNA technology to produce cuts in vector and other DNA molecules to obtain chimeric DNA.
So, the correct answer is option B.
Palindromic areas of DNA have
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Repetitive sequences
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Similar but opposite sequences in the two strands
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Low melting
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High melting
Explanation
The two-strand of the DNA has complementary base-pair sequences.
A palindromic sequence is the sequence of the DNA that reads the same from 5' to 3' on one strand and 5' to 3' on the complementary strand. It is also known as the inverted-reverse sequence.
So, the correct answer is option A.
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Practice Class 12 Medical Biology Quiz Questions and Answers
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