$A$ detritus food chain begins with which organism?

Which chemical is used in fire extinguishers? How is it harmful?

Non-biodegradable materials do not break down by the action of microorganisms. Will there be any effect of heat and pressure if they remain buried under the land for a long time?

Name the wastes which are generated in your house daily. What measures would you take for their disposal?

During heavy rain in a village,rainwater carried excessive fertilizers to a pond. How will it affect the fish population in the pond in the long run?

State one important function of ozone layer in the atmosphere. How is it formed there? Which compounds are responsible for the depletion of ozone layer? How do these compounds enter into the atmosphere?