A group of tissues with a common function is called an organ.

Here's a breakdown:

* Cells are the basic unit of life.

* Tissues are groups of similar cells that work together to perform a specific function.

* Organs are made up of different tissues working together to carry out a more complex function.

* Organ systems are groups of organs that work together to perform major bodily functions.

For example, your stomach is an organ made up of muscle tissue, epithelial tissue, connective tissue, and nervous tissue. All of these tissues work together to digest food.