Ontario Grade 9 Science Class Practice Exam

What is an Ecosystem?

1. A biological community of interacting organisms and their physical environment.

2. Space and all the matter and energy in it

3. A stream of electrically charged particles produced by the sun's corona

4. Scientific study of interactions among organisms and between organisms and their environment

The correct answer is: A biological community of interacting organisms and their physical environment.

An ecosystem is a complex system that includes living organisms and their non-living environment. It is an interconnected community made up of plants, animals, and microorganisms that interact with each other and their physical surroundings, such as water, air, and soil. Option A accurately describes the definition of an ecosystem, while the other options do not fully capture the concept. Option B describes the definition of the universe, not specifically an ecosystem. Option C describes the definition of sunspots, not an ecosystem. And option D describes the field of ecology, which is the study of ecosystems, but is not the definition of an ecosystem itself. Therefore, A is the correct answer.