ISC (Science) ISC Class 12 - CISCE Question Bank Solutions 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.

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

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.

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Define Racemose inflorescence

Name a plant which flowers every twelve years.

Name the terminal stage of ageing in the life cycle of plants.

Give a reason for the Following:

Pollen grains of wind-pollinated flowers are produced in large quantities.

Define the Stenothermal organisms.

Give the biological name of the following:

The mould from which penicillin is obtained.

Explain the different types of endosperms in angiosperms.