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

Explain mutualism with the help of any two examples.

Write what do phytophagous insects feed on.

Why do clown fish and sea anemone pair up? What is this relationship called?

How do mycorrhizae act as biofertilizers? Explain.

Suggest and describe a technique to obtain multiple copies of a gene of interest in vitro.

Given below is a list of six micro-organisms. State their usefulness to humans.

1. Nucleopolyhedrovirus
2. Saccharomyces cerevisiae
3. Monascus purpureus
4. Trichoderma polysporum
5. Penicillium notatum
6. Propionibacterium sharmanii

Why should we conserve biodiversity ? How can we do it?

Mention one advantage and one disadvantage to a farmer who uses them.

Draw a labelled sketch of sparged-stirred-tank bioreactor. Write its application.

State Gause’s competitive exclusion principle.

Name the type of association that the genus Glomus exhibits with higher plants.

Explain the significant role of the genus Nucleopolyhedrovirus in an ecological sensitive area.

Describe the mutual relationship between fig tree and wasp and comment on the phenomenon that operates in their relationship.

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