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

Explain briefly:

Chitinase

Name important defence mechanisms in plants against herbivory.

An orchid plant is growing on the branch of a mango tree. How do you describe this interaction between the orchid and the mango tree?

What is the ecological principle behind the biological control method of managing with pest insects?

Define the following term:

Commensalism

Define the following term:

Interspecific competition

Select the statement which explains best parasitism.

What are sacred groves?

Among the ecosystem services are control of floods and soil erosion. How is this achieved by the biotic components of the ecosystem?

'in-situ' Conservation can help endangered/threatened species. Justify the statement.

Name and describe any three causes of bio-diversity losses.

Mention any two examples where the organisms involved are commercially exploited in agriculture.

How is mutualism different from commensalism?

Why are baculoviruses considered good biocontrol agents?

Name a genus of fungi that forms a mycorrhizal association with plants.

State the difference in organic farmers approach from that of conventional pest control methods.

State the importance of using a bioreactor.

Organic farmers prefer the biological control of diseases and pests to the use of chemicals for the same purpose. Justify

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

Prepare a flow chart in formation of recombinant DNA by the action of restriction endonuclease enzyme EcoRI.