Science (English Medium) इयत्ता १२ - CBSE Question Bank Solutions

By what Latin name the first hominid was known?

Among Ramapithecus, Australopithecines and Homo habilis - who probably did not eat meat?

How do you express the meaning of words like race, breed, cultivars or variety?

We are told that evolution is a continuing phenomenon for all living things. Are humans also evolving? Justify your answer.

Choose the incorrect statement:

What do you understand by Snow-blindness?

At which stage during evolution did human use hides to protect their bodies and buried their dead?

It is generally observed that the children who had suffered from chickenpox in their childhood may not contract the same disease in their adulthood. Explain, giving reasons, the basics of such immunity in an individual. Name this kind of immunity.

A heavily bleeding and bruised road accident victim was brought to a nursing home. The doctor immediately gave him an injection to protect him against a deadly disease.

1. Write what did the doctor inject into the patient’s body.
2. How do you think this injection would protect the patient against the disease?
3. Name the disease against which this injection was given and the kind of immunity it provides.

State the cause of adenosine deaminase enzyme deficiency.

Name any two types of cells that act as ‘cellular barriers’ to provide innate immunity in humans.

How have human activities caused desertification? Explain.

Highlight the role of thymus as a lymphoid organ.

Why is secondary immune response more intense than the primary immune response in humans?

Discuss with your teacher what does ‘a suitable gene’ means, in the context of DNA vaccines.

Suggest a method to ensure an anamnestic response in humans.

What are interferons?

Mention role of interferons

Name the cells that are released from the above-mentioned gland. Mention how they help in immunity.

How do cytokine barriers provide innate immunity in humans?