Science (English Medium) Class 12 - CBSE Question Bank Solutions for Biology

What does H in’ ‘d’ and ‘III’ refer to in the enzyme Hind III?

Restriction enzymes should not have more than one site of action in the cloning site of a vector. Comment.

Restriction enzymes that are used in the construction of recombinant DNA are endonucleases which cut the DNA at ‘specific-recognition sequence’. What would be the disadvantage if they do not cut the DNA at specific-recognition sequence?

A plasmid DNA and a linear DNA (both are of the same size) have one site for a restriction endonuclease. When cut and separated on agarose gel electrophoresis, plasmid shows one DNA band while linear DNA shows two fragments. Explain.

How does one visualise DNA on an agarose gel?

A mixture of fragmented DNA was electrophoresed in an agarose gel. After staining the gel with ethidium bromide, no DNA bands were observed. What could be the reason?

Give the full form of ELISA. Which disease can be detected using it? Discuss the principle underlying the test.

Can a disease be detected before its symptoms appear? Explain the principle involved.

What is a recombinant DNA vaccine? Give two examples.

Why is it that the line of treatment for a genetic disease is different from infectious diseases?

Discuss briefly how a probe is used in molecular diagnostics.

Who was the first patient who was given gene therapy? Why was the given treatment recurrent in nature?

Taking examples under each category, discuss upstream and downstream processing.

Define Antigen and Antibody. Name any two diagnostic kits based upon them.

How is a mature, functional insulin hormone different from its prohormone form?

How is a mature, functional insulin hormone different from its prohormone form?

When a foreign DNA is introduced into an organism, how is it maintained in the host and how is it transferred to the progeny of the organism?

A patient is suffering from ADA deficiency. Can he be cured? How?

List the disadvantages of insulin obtained from the pancreas of slaughtered cows and pigs:

List the advantages of recombinant insulin.