Select the correct order of processing of PCR.

• Extension, primer annealing, denaturation

• Denaturation, primer annealing, extension

• Denaturation, extension, primer annealing

• Primer annealing, denaturation, extension

162.

Plasmid vector in DNA recombinant technology means

• a virus that transfers gene to bacteria

• extra-chromosomal autonomously replicating circular DNA

• sticky end of DNA

• any fragment of DNA carrying desirable gene.

An example of gene therapy is

• production of injectable hepatitis B vaccine

• production of vaccines in food crops like potatoes which can be eaten

• introduction of gene for adenosine deaminase in persons suffering from Severe Combined Immuno Deficiency (SCID)

• production of test tube babies by artificial insemination and implantation of fertilised eggs

Assertion: In recombinant DNA technology, human genes are often transferred into bacteria (prokaryotes) or yeasts (eukaryotes).

Reason: Both bacteria and yeasts multiply very fast to form huge populations which express the desired gene.

• 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.

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, tet^r and amp^r.

• 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