Test: Recombinant DNA Technology - NEET MCQ

Ribonuclease is the enzyme responsible for catalyzing the cleavage of RNA. RNA stands for ribonucleic acid. It is also known as RNase. It also cleaves the DNA-RNA hybrids.

Enzymes like lysozyme, cellulase, and chitinase are used to break down cell walls and release DNA from cells.

Agarose gel electrophoresis is used to check the progress of a restriction enzyme digestion by separating DNA fragments based on size.

Selectable marker genes like ampicillin resistance help in identifying and selecting cells that have taken up the recombinant DNA.

The restriction enzyme needs to be in pure form to cut the DNA. The restriction enzymes are molecular scissors that cleave the DNA at specific recognition sites. Restriction enzymes are also known as restriction endonucleases or restrictase.

The enzyme which cleaves DNA is DNase. It catalyzes the breakdown of phosphodiester linkages of DNA. It is a type of endonuclease. Ligases are the enzymes used in the joining of two strands.

A bioreactor is used to provide optimal conditions for cell growth, ensuring cells are in their physiologically most active phase.

Cellulase is the enzyme used for the lysis of plant cells. It catalyzes cellulolysis, which is the breakdown of cellulose. Cellulase acts on the glycosidic linkages of cellulose. Cellulose is mostly found in plant cell walls along with other components.

Downstream processing involves the separation and purification of the product before it is ready for marketing.

• A cloning vector with two antibiotic resistance genes (for tetracycline and ampicillin) allows differentiation between recombinant and non-recombinant cells.
• Foreign DNA insertion disrupts the tetracycline resistance gene, so recombinants lose resistance to tetracycline but retain resistance to ampicillin.
• Non-recombinants (without foreign DNA insertion) retain both tetracycline and ampicillin resistance, allowing them to survive on a medium containing both antibiotics.