Assertion : Restriction enzymes cut the strand of DNA to produce sticky ends.
Reason : Stickiness of the ends facilitates the action of the enzyme DNA polymerase.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
C.
If assertion is true but reason is false
A restriction enzyme or restriction endonuclease is an enzyme that cleaves DNA into fragments at or near specific recognition sites within the molecule known as restriction sites. Once restriction enzyme finds a recognition sequence, it binds and cut each of the two strands of the double helix at specific point leaving single stranded portions at the ends. This resulta in the overhanging stretches known as sticky ends.
These are so named because they form hydrogen bonds with their complementary counter parts ,ie, they can join similar complementary ends of DNA fragment from some other source with the help of DNA ligase. This stickiness of the ends facilitates the action of the enzyme DNA ligase, not DNA polymerase.
Which of the following is a cloning vector?
DNA of Salmonella typhimurium
Ti plasmid
Amp' and Tet' loci
Ori minus pBR322
In cloning of cattle a fertilized egg is taken out of the mother's womb and
in the eight cell stage, cells are separated and cultured untill small embryos are formed which are implanted into the womb of other cows
in the eight cell stage the individual cells are separated under electrical field for further development in culture media
from this upto eight identical twins can be produced
the egg is divided into 4 pairs of cells which are implanted into the womb of other cows.
How are transformants selected from nontransformants
Presence of more than one recognition site in the vector DNA.
Presence of alien DNA into the vector DNA results into insertional inactivation of selectable marker.
Antibiotic resistance gene gets inactivated due to insertion of alien DNA.
Both (b) and (c).
Which of the following is not a characteristic of pBR322 vector
It is the first artificial cloning vector constructed in 1977 by Boliver and Rodriguez.
It is the most widely used, versatile and easily manipulated vector.
It has two antibiotic resistance genes, tetr and ampr.
It does not have restriction site for Sal I.
What is a plasmid?
Bacterial, linear, dsDNA
Extrachromosomal linear RNA
Extrachromosomal circular dsDNA
Autonomously replicating circular RNA
Recombinant DNA technology involves several steps in which initial step is of isolation of the DNA. Which enzymes are used in the process for the breakdown of fungal cell, plant cell and bacterial cell respectively?
Lysozyme, lipases, trypsin
Chitinase, cellulase, lysozyme
Chitinase, cellulase, trypsin
Trypsin, lipases, cellulase
What is the source of EcoRI
Escherichia coli R I
Escherichia coli R I 13
Escherichia coli R Y 13
Escherichia coli RX 13
Which one of the following options is a correct match of phenomenon and its explanation
Reverse Transcription PCR - Many copies of a DNA sequence.
Central dogma - RNA > DNA > Protein > RNA.
RNA silencing - Use of ds-RNA to stop the expression of ss-RNA.
Transcription- Process of formation of RNA & proteins.
A tumor inducing plasmid widely used in the production of transgenic plants is that of
Escherichia coli
Bacillus thuringiensis
Staphylococcus aureus
Agrobacterium tumefaciens
