The correct option is **B. Natural biopolymers are usually biodegradable, whereas synthetic polymers are often resistant to degradation.** ### Detailed Explanation: 1. **Understanding Biopolymers and Synthetic Polymers:** - **Natural Biopolymers:** These are large molecules produced by living organisms. Common examples include proteins (made of amino acids), nucleic acids (like DNA and RNA), and polysaccharides (like starch and cellulose). They are typically made from renewable resources, such as plants and animals. - **Synthetic Polymers:** These are man-made polymers created through chemical processes. Examples include plastics like polyethylene, polystyrene, and nylon. They are usually derived from non-renewable resources, such as petroleum. 2. **Biodegradability:** - **Natural Biopolymers:** One of the key characteristics of natural biopolymers is their biodegradability. This means they can be broken down by microorganisms into simpler, non-toxic substances, often returning nutrients to the environment. For instance, cellulose can be decomposed by bacteria and fungi, making it environmentally friendly. - **Synthetic Polymers:** In contrast, many synthetic polymers are designed to be durable and resistant to degradation. This resistance is often a desired property for applications like packaging and construction, but it leads to environmental issues, as these materials can persist in the environment for hundreds of years without breaking down. 3. **Why Option B is Correct:** - The statement accurately reflects the general trend observed in natural versus synthetic polymers regarding biodegradability. Natural biopolymers are typically biodegradable, while synthetic polymers often resist degradation, leading to pollution and waste management challenges. ### Analysis of Other Options: - **Option A: Natural biopolymers are primarily derived from non-renewable resources, while synthetic polymers are renewable.** - This statement is incorrect. Natural biopolymers are derived from renewable resources (like plants and animals), while synthetic polymers are often made from non-renewable resources (like fossil fuels). - **Option C: Synthetic polymers are composed solely of amino acids, while natural biopolymers can include proteins, nucleic acids, and carbohydrates.** - This statement is misleading. Synthetic polymers can be made from a variety of monomers, not just amino acids. For example, synthetic polymers can be made from alkenes, which are not amino acids. Natural biopolymers include proteins (which are made of amino acids), nucleic acids, and carbohydrates, but this does not accurately describe synthetic polymers. - **Option D: Natural biopolymers are always more durable than synthetic polymers.** - This statement is also incorrect. While some natural biopolymers can be durable (like silk or chitin), many synthetic polymers are specifically designed for high durability and strength, often outperforming natural biopolymers in terms of mechanical properties and longevity. ### Summary: - Natural biopolymers are biodegradable, while synthetic polymers are often resistant to degradation. - Natural biopolymers are derived from renewable resources, whereas synthetic polymers typically come from non-renewable sources. - Synthetic polymers can be made from various monomers, not just amino acids. - Durability varies widely among both natural and synthetic polymers, and it is not accurate to claim that natural biopolymers are always more durable. This understanding of the differences between natural and synthetic polymers is crucial for discussions on environmental impact, material selection, and sustainability in chemistry and related fields.