Which trophic level has the highest energy in an ecosystem?

Write two characteristic features of energy flow in an ecosystem.

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

An ecosystem includes

Which of the following is not included in a freshwater ecosystem?

An ecosystem is an interacting system made up of $.......$