The Earth's core is divided into the liquid outer core (1,430 miles or 2,300 km radius) and the solid inner core (745 miles or 1,200 km radius).

Cumulus clouds are large, puffy, mid-altitude clouds with a flat base and a rounded top. These clouds grow upward and can develop into a cumulonimbus or thunderstorm cloud.

An exoskeleton (external skeleton) is common in arthropods like insects, spiders, and crustaceans.

Digestion begins in the mouth where the teeth and tongue break down food mechanically through chewing and saliva, via the enzyme salivary amylase, starts to break starches down chemically. From the mouth, food travels down the esophagus where contractions push the food into the stomach.

Part of the peripheral nervous system, the somatic nervous system is made up of nerve fibers that send sensory information to the central nervous system and control voluntary actions.