Definition
An endospore is a dormant, tough, and non-reproductive structure formed by some bacteria. Think of it as a bacterial 'survival pod.' Endospores allow bacteria to survive harsh conditions such as heat, radiation, and dehydration. They contain the bacterium's DNA and essential proteins. They can remain dormant for extended periods, even centuries. When conditions become favorable, the endospore can reactivate and the bacterium can resume normal function. It's like a bacterial hibernation mode.