Biodegradation is the disintegration of materials by bacteria, fungi, or other biological means. Below is an image of a biodegradable plastic bottle, where you can see the effects of biodegradation over time:
Snake molt, or "shed their skin" as the grow. Once the top layer of skin is too small, it is stretched to the the point that it splits, and the snake is able to slither out of the old skin casing, often leaving it in one piece:
Bromelain is a protein-digesting enzyme complex found in pineapple, and in higher concentrations, in the pineapple stem. It is able to hydrolyze or break down a wide variety of protein types in a range of both acid and alkaline environments.
While mushrooms might be the most familiar part of a fungus, most of their bodies are made up of a mass of thin threads, known as a mycelium. We now know that these threads act as a kind of underground internet, linking the roots of different plants. They help out their neighbors by sharing nutrients and information – or sabotage unwelcome plants by spreading toxic chemicals through the network.