Q 1 :    

What is the fate of a piece of DNA carrying only gene of interest which is transferred into an alien organism?      [2024]
A. The piece of DNA would be able to multiply itself independently in the progeny cells of the organism.
B. It may get integrated into the genome of the recipient.
C. It may multiply and be inherited along with the host DNA.
D. The alien piece of DNA is not an integral part of chromosome.
E. It shows ability to replicate.

Choose the correct answer from the options given below:

  • A and B only

     

  • D and E only

     

  • B and C only

     

  • A and E only

     

(3)

A piece of DNA when introduced in organisms is not able to multiply itself and can multiply only when it gets integrated into the genetic material of the recipient organism. This is because the alien piece of DNA has become a part of the recipient chromosome.

 



Q 2 :    

Which of the following can act as molecular scissors?                   [2023]

  • Restriction enzymes

     

  • DNA ligase

     

  • RNA polymerase

     

  • DNA polymerase

     

(1)

Restriction enzymes act as molecular scissors as these enzymes cut DNA duplex at some certain specific points called restriction sites.

 



Q 3 :    

The DNA molecule to which the gene of interest is integrated for cloning is called              [2015]

  • template

     

  • carrier

     

  • transformer

     

  • vector

     

(4)

Vector is a DNA molecule that carries a foreign DNA segment and replicates inside a host cell. The vector DNA and foreign DNA carrying gene of interest are cut by the same restriction endonuclease enzyme to produce complementary sticky ends. With the help of DNA ligase enzyme, the complementary sticky ends of the two DNAs are joined to produce a recombinant DNA (rDNA), which is then introduced into the host cell.

 



Q 4 :    

The cutting of DNA at specific locations became possible with the discovery of            [2015]

  • selectable markers

     

  • ligases

     

  • restriction enzymes

     

  • probes

     

(3)

Restriction enzymes recognise specific base sequences in a DNA molecule and cut its strands, e.g., EcoRI cuts DNA strands in the base sequence GAATTC.