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

Here's why the wording matters:

* Similar cells: Tissues are made up of cells with similar structure and function. This helps them perform their specialized task efficiently.

* Common function: The cells in a tissue work together to achieve a specific goal. For example, muscle tissue contracts to produce movement, while nervous tissue transmits signals throughout the body.

So, while tissues are made of similar cells, it's their shared function that truly defines them.