Science (English Medium) Class 12 - CBSE Important Questions for Biology

Name and explain the type of interaction that exists in mycorrhizae and between cattle egret and cattle.

Explain the different steps involved during primary treatment phase of sewage.

Explain the process of secondary treatment given to the primary effluent up to the point it shows significant change in the level of biological oxygen demand (BOD) it.

Why are the fruit juices bought from market clearer as compared to those made at home?

Name the bioactive molecules produced by Trichoderma polysporum and Monascus purpureus.

Name the source of streptokinase. How does this bioreactor molecule function in our body?

How do mycorrhizae act as biofertilizers? Explain.

Explain the function of “anaerobic sludge digester” in a sewage treatment plant.

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

Distinguish between the roles of flocs and anaerobic sludge digesters in sewage treatments.

How does the application of the fungal genus, Glomus, to the agricultural farm increase the farm output? 

By taking two examples explain how has bio-fortification helped in improving food quality.

How does the application of cyanobacteria help improve agricultural output?

Name the following:  Any one inter-specific hybrid mammal.

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.

"Man can be a primary as well as a secondary consumer." Justify this statement.

Bottled fruit juices are clearer as compared to those made at home. Explain.

Name the animals in which methanogens occur and the role they play there.

Explain the interrelationship between organic farming and biofertilizers, with the help of any three suitable examples.