system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does bruising a fruit make it go bad?
gpt
When you get a bruise on your arm, your body reabsorbs the blood from damaged vessels through various means. 
If you cut your arm off, there’s no immune system or circulatory system available to respond, so the blood in the bruise rots and spreads to the rest of your arm. 

It’s kinda like that.