The electromagnetic spectrum covers all possible wavelengths and frequencies of radiation. From lowest frequency (longest wavelength) to highest frequency (shortest wavelength) radiation: radio waves → microwaves → infrared waves → visible light → ultraviolet light → X-rays → gamma rays.

The heart is the organ that drives the circulatory system. In humans, it consists of four chambers with two that collect blood called atria and two that pump blood called ventricles. The heart's valves prevent blood pumped out of the ventricles from flowing back into the heart.

The acids produced by the pancreas contain several enzymes that aid in digestion. Lipase converts fat to glycerol and fatty acids. Pancreatic amylase breaks down complex carbohydrates into simple sugars. Trypsin converts polypeptides (the building blocks of protein) into amino acids.

Tertiary consumers eat primary consumers and secondary consumers and are typically carnivorous predators. Tertiary consumers may also be omnivores. Examples include wolves, sharks, and human beings.

A warm front is the boundary between warm and cool (or cold) air when the warm air is replacing the cold air. Warm air at the surface pushes above the cool air mass creating clouds and storms.