Have you ever seen a really big tree or a huge mushroom? Well, those are examples of the largest organisms on Earth!
Organisms are living things, like plants and animals. Some organisms can grow really, really big!
One of the largest organisms is a tree called the General Sherman tree. It's located in California and it's really tall and wide. It's so big that it would take more than 20 grown-ups holding hands to fully circle around it!
Another example is a type of fungus called Armillaria ostoyae. This mushroom is found in the United States and is known to grow underground. It's so massive that it covers over 2200 acres of forest!
These organisms can grow so big because they have been around for a very long time and have had time to grow and spread. Imagine a tiny seed growing into a giant tree over hundreds of years!
So, in summary, some organisms like trees and mushrooms can grow really big and become the largest organisms because they have been around for a long time and had time to grow and spread.