Question

An ecosystem must have a continuous external source of
A. Minerals
B. Energy
C. Food
D. All of the above

Answer 1

Hint: Energy as trophic levels can be transferred from one organism to another organism by eating or being eaten by others. This energy cycle and shifting of energy from one living organism to another results in the outset of energy flow through almost all food webs present.

Complete answer: Minerals are naturally occurring inorganic components or compounds possessing a systematic internal structure along with the characteristic chemical configuration, crystal form, as well as physical properties. Common minerals comprise quartz, feldspar, mica, amphibole, olivine, and calcite.
a) Energy - The energy cycle in the ecosystem is one of the crucial factors which helps the survival of such a great number of organisms. For almost all living organisms on earth, the fundamental source of energy is solar energy.
b) Food - A food is a substance which living organisms take in to live. The food chain displays how energy is transferred from one living organism to another via the food chain. All the living organisms need to comprehend how the food chain works so that one knows what are the important living organisms that make up the food chain and how the ecology is balanced.
So, the correct answer is option B.

Note: The sun is the majority source of energy for all living organisms and it is the part of the ecosystem. Producers like plants, algae, along with cyanobacteria utilise energy from the sun to make an organic substance called glucose from carbon dioxide and water.