Convection is the transfer of heat by the circulation or movement of the heated parts of a liquid or gas. Examples of heat transfer by convection include water coming to a boil on a stove, ice melting, and steam from a cup of coffee.

If no oxygen is present, cellular respiration is anaerobic and will result in fermentation where either lactic acid or alcohol is used instead of oxygen.

Chemical waste like excess water, minerals, and salt are filtered from the blood by the kidneys and secreted into the urine. Urine is transported from the kidneys to the bladder through ureters.

Mantle makes up 84% of the Earth's volume and has an average thickness of approximately 1,800 miles (2,900 km). It is dense, hot, and primarily solid although in places it behaves more like a viscous fluid as the plates of the upper mantle and crust gradually "float" along its circumference.

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