That's a great question! It's true that many multicellular organisms contain trillions of cells.

Here's a breakdown:

* Humans: We are estimated to have around 37.2 trillion cells.

* Other Large Organisms: Animals like elephants and whales likely have even more cells.

* Smaller Organisms: Smaller multicellular organisms, like insects or plants, have far fewer cells, but still many millions or billions.

It's important to remember that this is a rough estimate. The exact number of cells in an organism can vary depending on factors like size, age, and health.

So, while "trillions" is a good general number for larger multicellular organisms, it's not a hard and fast rule.