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

Explain the role of stem cells in medical treatment.

Explain the term biofortification.

What is cryopreservation?

In humans, somatic gene therapy was carried out to correct an immunodeficiency disease. Name this disease.

Give a reason for the following:

Streptokinase is administered to the patients having myocardial infarction.

The diagram given below represents the schematic structure of proinsulin, which undergoes certain modifications before it becomes a fully functional insulin.

Study the diagram carefully and answer the questions that follow:

1. State the change the proinsulin undergoes to become fully functional.
2. Name the modern scientific technique used for the production of human insulin.
3. How are the two polypeptide chains of the fully functional insulin held together?

How many cycles of PCR are required to produce 250 molecules of DNA, starting with a single parental strand?

Name the technique used to detect the presence of HIV in the body of an individual, Justify the principle associated with this technique.

Define the Stenothermal organisms.

Mention the scientific name of protozoan parasite that causes Amoebiasis.

The diagram given below shows the life cycle of a malarial parasite. Study it carefully and answer the questions that follows:

1. Name the hosts in which the asexual phase and sexual phase of the life cycle takes place.
2. Identify the infective stage labelled ‘D’.
3. Name the structure labelled ‘A’ and ‘E’.
4. Give any one symptom of malaria.

Some orchids live on the branches of mango trees. Name the type of interaction that exists between the mango tree and the orchid.

What happens to an inferior competitor if a superior competitor is present in the same environment?

What happens to an inferior competitor if the superior competitor is removed from the environment?

Which organisms constitute the last trophic level?

Answer the following question:

Why do Green plants start evolving CO₂ instead of O₂, at high temperatures?

Give a reason for each the following: 

Climax stage is achieved quickly in secondary succession as compared to primary succession.

Give a graphic representation of the Hatch Slack or C4 cycle.

With reference to the levels of an organisation, differentiate between living organisms and non-living objects.

Give a graphic representation of the C₃ cycle.