Which cells of the skin are filled with a tough, fibrous protein and account for most of the epidermal cells of the skin?

Keratinocyte

Explanation:

Keratinocytes are primarily found in epidermis and its made up of 90% epidermal skin in man.

keratinocytes forms barrier that prevent us against environmental damage by heat, ultraviolet radiation, water loss from the skin, invasion of pathogenic bacteria, fungi, parasites, and viruses.

Keratinization is a form of the physical barrier formation where more keratinocytes is produced under terminal differentiation.

answer:

convection currents in the magma drive plate tectonics. heat generated from the radioactive decay of elements deep in the interior of the earth creates magma (molten rock) in the aesthenosphere. the aesthenosphere (70 ~ 250 km) is part of the mantle, the middle sphere of the earth that extends to 2900 km.