Biotechnology and its Applications — BIOLOGY STD 12 Science — Question

What is meant by ozone hole? Which unit is used for measuring ozone thickness?

Many proteins are secreted in their inactive form. This is also true of many toxic proteins produced by micro organisms. Explain how the mechanism is useful for the organism producing the toxin?

When and where was the World Summit on sustainable development held? How many countries signed the convention? What was the objective?

Global carbon is fixed in the biosphere through photosynthesis. Explain any two ways by which carbon is returned to the atmosphere.

Write a short note on adaptations of animal pollinated flowers.

Explain the following terms with example.
Co-dominance.

In angiosperms, zygote is diploid while primary endosperm cell is triploid. Explain.

In view of the current food crisis, it is said, that we need another green revolution. Highlight the major limitations of the earlier green revolution.

Why does biomagnification occur with certain substances? Name two such substances.

Who was the first to construct rDNA? Name the bacterium whose plasmid was used. How was it possible to cut the specific genes/ DNA?