What is a common characteristic of natural polymers?

Natural polymers are materials that are produced by living organisms and consist of biological sources. This characteristic makes them distinct from synthetic polymers, which are man-made through chemical processes. Examples of natural polymers include proteins, polysaccharides, and nucleic acids, all of which play vital roles in biological functions and structures.

Natural polymers typically exhibit a variety of properties depending on their composition and structure, such as flexibility, elasticity, and biodegradability. Their biological origin allows them to be integrated seamlessly into living systems, leading to their use in various applications, such as biocompatible materials for medical devices.

While some natural polymers may break down easily, not all do, and their rigidity or hardness can vary widely; thus, the characteristics of being completely synthetic or always being rigid and hard do not apply to them.