Biology is the scientific study of life. Once people believed that living things contained a vital life force and nonliving things did not. While people don't believe this anymore, living things differ from nonliving things. It turns out there are five characteristics that distinguishes living things from nonliving things. A living organism must exhibit all these characteristics.
Other People Are Reading
All living things are made up of cells. Cells are the basic building blocks of life. They are made of living material separated by a cell wall, or barrier, and are so small you can only see them with a microscope. Your blood, bones, fingernails, hair, muscles, nerves and skin are made up of cells. Cells work together to keep you alive. They use energy, grow and reproduce.
All living things respond to external environmental stimuli. You use your five senses to detect and respond to changes in heat, light and sound, for example. The ability to adjust and respond to environmental changes is important because it allows living things to maintain a constant internal environment necessary for life called homeostasis. You might move to find food, to find shelter or to avoid danger.
All living things metabolise. Metabolism is a series of chemical reactions that take place within the body's cells. It converts the food you eat into the energy you need to power everything you do, from growing to moving to thinking. Metabolism begins when you are conceived and ends when you die. If metabolism stops, living things die.
All living things reproduce. Sexual reproduction is the process of two living things creating another living thing. The genetic material carried within the DNA molecules passes from one generation to the next, and the offspring exhibit their parents' genetic characteristics. While individual organisms die, reproduction ensures that the species will continue. However, if individual death rates exceed reproduction rates, extinction of the species will occur.
All living things adapt to changes in their environment. Through the process of natural selection, organisms within a population evolve characteristics that allow them to survive in particular environments. When change occurs in populations, the population becomes better able to respond, metabolise and reproduce. This leads to a proliferation of populations of new living organisms, which is unique to living things.
- 20 of the funniest online reviews ever
- 14 Biggest lies people tell in online dating sites
- Hilarious things Google thinks you're trying to search for