An electrostatic precipitator in a thermal power plant is not able to generate high voltage of several thousands. Write the ecological implication because of it.

What is a trophic level in an ecosystem? What is ‘Standing crop’ with reference to it?

93.

Explain the role of the ‘first trophic level’ in an ecosystem.

How is the detritus food chain connected with the grazing food chain in a natural ecosystem?

Biotic factors are :

• chemical factors of soil which affect life

• physical factors of soil which affect life

• all living organisms which influence other organisms

• factors of atmosphere which affect life

Which of the following would appear as the pioneer organisms on bare rocks?

• Liverworts

• Mosses

• Green algae

• Green algae

The term ecosystem was coined by

• AG Tansley

• E Haeckel

• E Warrning

• E Warrning

Secondary productivity is rate of formation of new organic matter by

• producer

• parasite

• consumer

• consumer

Natural reservoir of phosphorus is 

• sea water

• animal  bones

• rock

• rock

During  sewage treatment, biogas are produced, which include

• methane, hydrogen sulphide and carbon dioxide

• methane, oxygen and hydrogen sulphide

• hydrogen sulphide, methane and sulphur dioxide

• hydrogen sulphide, methane and sulphur dioxide