Which term describes matter that makes up living and dead organisms in an ecosystem?

• A. Abiotic matter
• B. Carbon dioxide
• C. Biotic matter
• D. Ecosystem

Answer: (C)

The main idea here is distinguishing living (and once-living) components from nonliving parts in an ecosystem. Biotic matter covers all material that comes from living organisms, including the bodies of plants and animals as well as remains like detritus and waste. That’s why it’s the best term for matter that makes up living and dead organisms in an ecosystem. Abiotic matter refers to nonliving elements such as minerals, water, air, and sunlight, which is why it doesn’t fit. A specific molecule like carbon dioxide is not the category being asked for, and an ecosystem describes the whole interacting system, not a type of matter. A fallen leaf or a dead insect is biotic matter, while sand or rock is abiotic.