Blood Types. Distinct molecules called agglutinogens (a type of antigen) are attached to the surface of red blood cells. There are two different types of agglutinogens, type A and type B.
Fossil fuels are hydrocarbons, primarily coal, fuel oil or natural gas, formed from the remains of dead plants and animals. In common dialogue, the term fossil fuel also includes hydrocarbon-containing natural resources that are not derived from animal or plant sources.
Because fossil fuels form from the remains of plants and animals, all fossil fuels contain carbon, too. Most of the carbon in fossil fuels exists as hydrocarbons, which are hydrogen-carbon compounds. Fossil fuels may exist as liquids, gases, or solids.Liquid Fossil Fuels: Petroleum A liquid mixture of complex hydrocarbon compounds is called petroleum.oal is a fossil fuel that forms underground from partially decomposed plant material. Coal was once the major source of energy in the United States. When fossil fuels, including coal, are burned, most of the energy released is heat.