All living organisms respond to stimuli, grow and change, reproduce to create offspring, maintain a stable body temperature, metabolize energy, consist of one or more cells, and pass on their individual genetic traits. F... More »

Living things have the following six characteristics that define life: they are made of cells, they use energy, they grow, they reproduce, they respond to their environment and they self-regulate. A seventh characteristi... More »

Acids share several common characteristics and properties, including sour taste and corrosion to all metals. These characteristics distinguish acids from bases, which culminate the second broad class of chemical substanc... More »

Neanderthals (also spelled "Neandertals") were shorter and more stocky than homo sapiens. Their faces were also much larger and wider, and they sported a wider nose. These adaptations made it easier for them to live in c... More » History Prehistory

The Virtual Fossil Museum states that Precambrian fossils mostly derive from organisms called stromatolites. Stromatolites are presumed to be among the world's oldest fossils. The existence of stromatolites is important,... More » History Prehistory

During the Paleozoic Era, there were multi-cellular organisms like trilobites, mollusks, jawless fish, seaweeds and finally, jawed fish, sharks, plants and early amphibians and reptiles. At the beginning, there was an in... More »

During the Precambrian Era, single-celled organisms, bacteria, microbes and some multi-cellular organisms existed. The Precambrian Era is split into the Hadean, Archaean and Proterozoic eons. More »