Blood transfer is limited by the type and Rh factor of the blood. Someone who has Rh-factor negative blood cannot receive blood with a positive type but a person with Rh-factor positive type blood can receive Rh-negative blood. Type O negative blood is the universal donor because it can be given to a person with any blood type. Type AB positive is the universal recipient meaning someone with this blood type can receive any other type of blood.

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.

The broadest classification of life splits all organisms into three groups called domains. The three domains of life are bacteria, archaea and eukaryota.

Tides are caused by the gravitational interaction of Earth and the Moon.

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.