Final answer:
Tectonic plates can consist of continental lithosphere, oceanic lithosphere or both. Continental lithosphere is thicker and less dense than oceanic one, which is denser and thinner. Most tectonic plates are composed of both types of lithosphere.
Step-by-step explanation:
The plates in question can be made up of continental lithosphere, oceanic lithosphere, or a combination of both. The continental lithosphere consists of the continental crust and the portion of the mantle underneath it. It's less dense and thicker compared to the oceanic lithosphere. The oceanic lithosphere, on the other hand, comprises the oceanic crust and the uppermost mantle below. It is denser and thinner. Most tectonic plates are comprised of both continental and oceanic lithosphere.
Learn more about Tectonic Plates