What do you call substances that are made from or are the remains of living things?

The term "organic matter" is used to describe substances that are derived from or consist of the remains of living organisms. This includes materials such as plant debris, animal remains, and residues from metabolic processes. Organic matter is a crucial component of ecosystems as it contributes to soil fertility, provides energy for decomposers, and supports the growth of plants and other organisms.

Understanding organic matter is essential in the context of aquatic environments because it plays a significant role in nutrient cycling, supporting aquatic food webs. For example, organic materials break down and release nutrients that are essential for the growth of aquatic plants and algae, which form the base of the food chain in many aquatic ecosystems. This differentiation from "inorganic materials," which are non-living and do not comprise organic compounds, highlights the significance of understanding the contributions of organic matter in ecological systems.

While biological materials could encompass both organic and inorganic substances, the specific definition of organic matter focuses solely on those derived from living organisms. Natural resources refer to a broader category that includes materials found in nature, which may or may not be organic, and is not exclusively tied to the remains of living things.