Restriction endonucleases are enzymes which

1. make cuts at specific positions within the DNA molecule

2. recognize a specific nucleotide sequence for binding of DNA ligase

3. restrict the action of the enzyme DNA polymerase

4. remove nucleotides from the ends of the DNA molecule

Stirred-tank bioreactors have been designed for

1. addition of preservatives of the product

2. purification of the product

3. ensuring anaerobic conditions in the culture vessel

4. availability of oxygen throughout the process

Which one of the following is commonly used in transfer of foreign DNA into crop plants?

1. Trichoderma harzianum

2. Meloidogyne incognita

3. Agrobacterium tumefaciens

4. Penicillium expansum

Polyethylene glycol method is used for

1. gene transfer without a vector

2. biodiesel production

3. seedless fruit production

4. energy production from sewage

Gel electrophoresis is used for

1. cutting of DNA into fragments

2. separation of DNA fragments according to their size

3. construction of recombinant DNA by joining with cloning vectors

4. isolation of DNA molecule

The linking of antibiotic resistance gene with the plasmid vector became possible with

1. DNA ligase               

2. endonucleases

3. DNA polymerase       

4. exonucleases

Microbes found to be very useful in genetic engineering are:

1. Escherichia coli and Agrobacterium tumefaciens

2. Vibrio cholerae and a tailed bacteriophage

3. Diplococcus sp. and Pseudomonas sp.

4. Crown gall bacterium and Caenorhabditis elegans

Restriction endonuclease :

1. cuts the DNA molecule-randomly

2. cuts the DNA molecule at specific sites

3. restricts the synthesis of DNA inside the nucleus,

4. synthesizes DNA

Which of these are most widely used in genetic engineering?

1. Plastid

2. Plasmid

3. Mitochondrion

4. Ribosome

Introduction of  foreign genes for improving genotype is

1. biotechnology 

2. vernalization

3. tissue culture

4. genetic engineering