Life. No one ever really thinks about it, either something is alive or it isn't. Take a rock for example: it doesn't take a genius to conclude that it isn't alive. Although with more complex things, like a human or an animal, we know they are alive, but we don't know exactly how or why. When someone is asked “Is that leaf alive? How do you know?" and they answer yes, the next common response is "I don't know, I just am!" There are seven characteristics of life that will indisputably determine whether a subject is actually alive or not. Take for example a horse thoroughbred racing, they are obviously alive, demonstrating that being made of cells, they are able to regulate homeostasis, reproduce, grow and develop, have a metabolism, respond to stimuli and show biological evolution. One of the characteristics of life is that the organism is made of cells. Thoroughbreds are multicellular organisms, which means that their cells are eukaryotic and specialized, easily demonstrated by the lightning-fast hooves on their lower legs, they may seem indestructible, but in reality they are not. at all. They are made of living bones covered in keratin and proteins. Keratin is a scleroprotein and, like collagen, elastin and fibroin, its purpose is to form connective tissue, bone matrices and tendons. Keratin is produced in cells and is important in horns, hair, hooves and skin cells. In the specific case of hooves, it attaches and bonds to the living bone that constitutes its shell. Hooves are just an example of the cells they have, their internal systems have millions upon millions of cells. Red blood cells to carry oxygen, white blood cells to help the immune system and also DNA cells. Secondly, the ability to regulate an internal system is demonstrated,...... middle of paper....... The purebred breed originated in England in the 17th century, but quickly spread throughout the world in the 18th and 19th century. The native mares were crossed with Arabian, Barb and Turkmen stallions. Any modern Thoroughbred can trace their pedigrees to three original stallions imported to England in the 17th century. They are the only breed that can consistently reach speeds of 40 miles per hour thanks to their physique. They are at least 15hh but can be well over 17hh with usually solid coats, only rarely are white purebreds or palominos found. In conclusion, using the seven characteristics of life is a very accurate way to demonstrate the life of an object or organism. If studied thinking about the seven parts, metabolism, homeostasis, reaction to stimuli, reproduction, growth and development, made of cells and biological evolution.