. Why are some substances biodegradable and some non biodegradable
Ans: The reason why some substances are biodegradable and some non-biodegradable is because the microorganisms like bacteria and decomposers like saprophytes have a specific role to play. They can breakdown only natural products like paper, wood, etc. but they cannot breakdown man-made products like plastics. Based on this, some substances are biodegradable and some non-biodegradable.