Restriction enzymes:

1. are endonucleases which cleave DNA at specific sites

2. make DNA complementary to an existing DNA or RNA

3. cut or join DNA fragments

4. are required in vectorless direct gene transfer

A tumor inducing plasmid widely used in the production of transgenic plants is that of

1. Escherichia coli

2. Bacillus thuringiensis

3. Staphylococcus aureus

4. Agrobacterium tumefaciens.

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.

Hirudin is

(1) a protein produced by Hordeum vulgare, which is rich in lysine

(2) a toxic molecule isolated from Gossypium hirsutum, which reduces human fertility 

(3) a protein produced from transgenic Brassica napus, which prevents blood clotting

(4) an antibiotic produced by a genetically enginnered bacterium, Escherichia coli 

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?

(1) Lysozyme, lipases, trypsin

(2) Chitinase, cellulase, lysozyme

(3) Chitinase, cellulase, trypsin

(4) Trypsin, lipases, cellulase

What is the source of EcoRI?

(1) Escherichia coli R 1

(2) Escherichia coli R I 13

(3) Escherichia coli R Y 13

(4) Escherichia coli R X 13

Which of the following is a cloning vector?

(1) DNA of Salmonella typhimurium

(2) Ti plasmid

(3) Amp' and Tet' loci

(4) Ori minus PBR322

Which of the following is a palindromic sequence?

(1) 5'-CGTATG-3'           

      3'-CGAATG-5'

(2) 5'-CGAATG-3'

     3'-GCATAC-5'                 

(3) 5'-GAATTC-3'

     3'-CTTAAG-5'      

(4) 5'-GACTAC-3'

     3'-CTTAAG-5'      

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.