Which radiations are prevented from reaching the Earth by the ozone layer?

$(a)$ What percentage of energy available at the producer level is transferred at successive trophic level in a food chain?
$(b)$ What percentage of the solar energy is trapped and utilised by the plants?

Choose one consumer each that belongs to the second and third trophic levels from the organisms given below:
Eagle,frog,tiger,rabbit,fox

In a food chain,the third trophic level is always occupied by

What are the by-products of fertiliser industries? How do they affect the environment?

The most important compound which accounts for almost $80\%$ of the total depletion of the ozone layer is $.........$