A biome is a large naturally occurring community of flora (plants) and fauna (animals) occupying a major habitat (home or environment).

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.

Momentum is a measure of how difficult it is for a moving object to stop and is calculated by multiplying the object's mass by its velocity: \(\vec{p} = m\vec{v}\). Like velocity, momentum is a vector quantity as it expresses force applied in a specific direction.

The spinal cord connects the brain to the body's network of nerves. It carries impulses between all organs and the brain and controls simple reflexes.

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.