The planet Earth itself is considered to be a closed system because there is a limit to the amount of matter that is exchanged. However, there are open systems that are ON Earth.
Answer:
After Eris was discovered, they had to decide whether Eris was a planet or not. If they decided it wasn't a planet, they had to also decide whether Pluto should be counted as a planet since Eris and Pluto were quite similar. They were the same size, and they were both part of the Kuiper Belt.
Explanation:
The difference between an organ and a tissue is that basically tissues are a group of similar cells that works together. Then a group of tissue that works together would make up an organ. Groups of organ working together later makes up an organ system. This is the main difference between an organ and a tissue.