Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions for Biology

Discuss the importance of testing of new plant varieties in a geographically vast country like India.

Define the term ‘stress’ for plants. Discuss briefly the two types of stress encountered by plants.

Discuss natural selection and artificial selection. What are the implications of the latter on the process of evolution?

Give few examples of biofortified crops. What benefits do they offer to the society?

You are a Botanist working in the area of plant breeding. Describe the various steps that you will undertake to release a new variety.

Mutations are beneficial for plant breeding. Taking an example, justify the statement.

Discuss briefly the technology that made us self-sufficient in food production.

Mycorrhiza does not help the host plant in ______.

Which one of the following is not a nitrogen-fixing organism?

Why are blue green algae not popular as biofertilisers?

How do mycorrhizal fungi help the plants harbouring them?

Why are cyanobacteria considered useful in paddy fields?

Give two examples of biofertilizer.

Pyramid of numbers is ______.

What does the base tier of the ecological pyramid represent?

Name any two organisms which can occupy more than one trophic level in an ecosystem.

Organisms at a higher trophic level have less energy available. Comment.

The number of trophic levels in an ecosystem are limited. Comment.

What are the shortcomings of ecological pyramids in the study of ecosystems?

What are the three types of ecological pyramids? What information is conveyed by each pyramid with regard to structure, function and energy in the ecosystem?