Question

An ecosystem, such as an aquarium, is self-sustaining if it involves the interaction between organisms, a flow of energy, and the presence of

• A. Equal numbers of plants and animals
• B. More animals than plants
• C. Materials cycles
• D. Pioneer organisms

Answer 1

The correct option is C Materials cycles

If a ecosystem such as an ecosystem is to be self-sustaining, materials such as oxygen, carbon dioxide, water and nitrogen must be able to recycle between the organisms.

Therefore, the correct answer is option C.