Science (English Medium) Class 12 - CBSE Question Bank Solutions

State True/False with explanation.

Abortions could happen spontaneously too.

Design a test-cross.

Can you list 10 recombinant proteins which are used in medical practice? Find out where they are used as therapeutics (use the internet).

From what you have learnt, can you tell whether enzymes are bigger or DNA is bigger in molecular size? How did you know?

Besides better aeration and mixing properties, what other advantages do stirred tank bioreactors have over shake flasks?

Can you recall meiosis and indicate at what stage recombinant DNA is made?

Describe briefly the following:

Bioreactors

Describe briefly the following:

Downstream processing

Explain briefly:

PCR

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.

1. One organism is benefited
2. Both the organisms arc benefited
3. One organ is benefitted, other is affected.
4. One organism is benefited, other is affected

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.