Which of the Following Are True About Ecosystems? Check All

Multiple Choice

Which of the following are true about ecosystems? Check all that apply.

A) They contain both living and nonliving components.
B) There is a transfer of energy through the system and some energy is lost as heat energy.
C) Nutrients repeatedly cycle through the ecosystem.
D) They represent the lowest level of biological organization.
E) The ultimate source of energy for most ecosystems is the sun.