ISC (Science) ISC Class 12 - CISCE Important Questions for Biology (Theory)

Which molecules are called molecular scissors? Why are they called so?

The rDNA technology has provided a method to control the nematode parasite Meloidogyne incognita. Explain the principle involved in this technique.

Name the source of thermostable DNA polymerase.

How many sets of primers are required in each cycle of PCR?

Which one of the following enzymes is used to join DNA fragments? 

Give a reason for the following:

DNA cannot enter directly into the host cell.

State the steps involved in the process of gene therapy for the treatment of ADA-deficiency.

Study the diagram given below and answer the questions that follow.

1. Name the cloning vector shown above. In which organism in this cloning vector inserted?

2. Mention any two restriction sites shown in the diagram.

3. Name any two selectable markers shown in the diagram.

Give the name of the target pest of gene cry 1 Ac.

Assertion: In a bioreactor, it is not necessary to maintain sterile ambience.

Reason: Sterile conditions promote the growth of unwanted microbes in the culture medium.

Suneeta is planning an experiment to clone a gene in a vector. So, she has to choose a good cloning vector.

Which one of the vectors shown below should she choose? Justify your answer by giving two reasons.

Vector A	Vector B	Vector C

Assertion: E. coli was transformed by inserting the foreign DNA by using Pvul in pBR322.

Reason: It was done to make the transformed cells survive in the culture medium containing ampicillin.

David is a molecular biologist. He uses a technique to know the amino acids occupy the first and the last positions in the Chain - A and Chain - B of insulin. Name the scientist whose contribution made it possible for David to use this technique.

Give a reason for the following:

The diagram given below represents vector pBr322 which was modified by a research scholar Dr. Rayon, but the vector was rejected by his guide.

What is mycoherbicide?

Scientific term for the hydrostatic pressure developed inside the cell on the cell wall due to endosmosis.

Give four points of anatomical differences between a monocot stem and a dicot stem

Explain how insulin can be produced using recombinant DNA technology.

In the following questions/statements has four suggested answers. Rewrite the correct answer

Bt cotton is resistant to:

(A) Insects

(B) Herbicides

(C) Salt

(D) Drought

State the best-known contribution of P.K. Sethi