Science (English Medium) कक्षा १२ - CBSE Important Questions for Biology

What is biopiracy?

Explain the effect on the characteristics of a river when urban sewage is discharged into it.

Name any two biodiversity hot spots in India.

Draw a diagram of the mature embryo sac of an angiospermic ovule and label any four parts in it.

Medically it is advised to all young mothers that breast-feeding is the best for their newborn babies. Do you agree? Give reasons in support of your answer.

Explain menstrual cycle in human females.

How can the scientific understanding of the menstrual cycle of human females help as a contraceptive measure?

Explain the mechanism of 'sex determination' in birds. How does it differ from that of human beings?

Write the names of the following:

A 15 mya primate that was ape-like

Write the names of the following:

A 2 mya primate that lived in East African grasslands

With the help of an algebraic equation, how did Hardy-Weinberg explain that in a given population the frequency of occurrence of alleles of a gene is supposed to remain the same through generations?

How do cytokine barriers provide innate immunity in humans?

Name the source plant of heroin drug. How is it obtained from the plant?

Your advice is sought to improve the nitrogen content of the soil to be used for cultivation of a non-leguminous terrestrial crop.

1. Recommend two microbes that can enrich the soil with nitrogen.
2. Why do leguminous crops not require such enrichment of the soil? 

Give an example of a bacterium, a fungus and an insect that are used as biocontrol agents.

How has the development of bioreactor helped in biotechnology?

Name the most commonly used bioreactor and describe its working.

Explain the roles of the following with the help of an example each in recombinant DNA technology :

Restriction Enzymes

Explain the roles of the following with the help of an example each in recombinant DNA technology :

Plasmids

Represent diagrammatically three kinds of age-pyramids for human populations.