Final answer:
The lithosphere is the part of Earth made up of tectonic plates which float on the semi-fluid asthenosphere.
Step-by-step explanation:
The part of Earth that is made up of tectonic plates is called the lithosphere. The lithosphere consists of the crust and the rigid upper part of the mantle. It is divided into several large and small plates that float on the semi-fluid asthenosphere.
Learn more about Tectonic plates