In the given food chain,suppose the amount of energy at the fourth trophic level is $5 \, kJ$,what will be the energy available at the producer level? (in $kJ$)
Grass $\rightarrow$ Grasshopper $\rightarrow$ Frog $\rightarrow$ Snake $\rightarrow$ Hawk

Give the full form of $CFC$.

What would be the consequence if all the herbivores are removed from a grassland ecosystem?

What will be the amount of energy available to the organisms of the $2^{\text{nd}}$ trophic level of a food chain,if the energy available at the first trophic level is $10,000 \, J$?

What percentage of ozone layer depletion was recorded in the South Pole region?

Suggest one word for each of the following statements/definitions:
$(a)$ The physical and biological world where we live in
$(b)$ Each level of food chain where transfer of energy takes place
$(c)$ The physical factors like temperature,rainfall,wind and soil of an ecosystem
$(d)$ Organisms which depend on the producers either directly or indirectly for food