To provide oxygen to the body, blood flows through the heart in a path formed by the right atrium → right ventricle → lungs → left atrium → left ventricle → body. When blood enters the right side of the heart it is deoxygenated. It enters the left side of the heart oxygenated after traveling to the lungs.

The liver produces bile which emulsifies (separates) fat.

Smaller rocks shed by asteroids and comets are called meteoroids. When these rocks reach Earth's atmosphere, they burn up in the mesosphere and become meteors. If a meteor manages to reach the Earth, it is called a meteorite.

A substance undergoes a phase transition when it moves from one state of matter to another, for example, when water freezes or boils.

The narrowest classification of life, species, contains organisms that are so similar that they can only reproduce with others of the same species.