What is Life? Life is the totality of life which exists through biological metabolism, activity, functions, reacts, assesses, and grows through time. The key difference between living things and non-living matter is that living things use energy for living and cellular growth. Non-living matter consists of atoms, molecules, cells, and fibers without any inner structure (including nerve, muscle, and bone tissues). A living thing is living by using energy from the environment to grow and develop.
All living organisms reproduce through a process called reproduction. This reproductive process involves separating one individual or group of organisms from its environs, mating with another organism, forming a new living organism, and growing into a self-sustaining entity. This process occurs continually throughout the entire universe.
What is Life? In the most comprehensive scientific definition, Life is "the entire web of connectedness, mutual aid, and life-bearing capacity of all forms of living things". In a more specific scientific definition, Life is "the processes that generate and maintain the continuity of life in diverse environments". These definitions are highly inclusive and reflect a recognition that all living organisms reproduce through living processes.
How do living organisms reproduce? Through the process of sexual reproduction. This process involves a sperm and an egg, held together by some form of protein glue. The male sperm swims through the female's vagina where it deposits the egg. The egg is carried by the female for a period of time until it is fertilized by either a living sperm or a nonliving sperm. If the sperm is dead, it does not fertilize the egg.
How do living organisms develop over time? Through a process of generation and evolution. The older an organism is, the more genes it possesses and the longer it can reproduce. It is possible that a species that has existed for millions of years reproduced without any help from another living organism. It is also possible that the species could be a very old and very well preserved, yet still produce offspring that are very recently developed.
In our scientific definition, Life is defined as "an incessant process of generation". Life is a critical process and is not only produced by living organisms, but also by non-living ones such as in the chemical reactions that form rocks and coral reefs. Because it is so important to the existence of all of us that this definition includes both living and nonliving organisms.
The DNA of each cell contains instructions for making a cell. These cells together form the structure of what we know as an organism. However, unlike plants and animals, an organism does not reproduce by means of a sexual process, but rather by a process known as biogenesis. In other words, according to scientists, an organism is something that forms either only by living processes or by forming a cellular orifice that allows some form of communication to take place.
What is Life? This question has been at the forefront of research for many years now. Biologists have used the fossil record to determine the age of various organisms. They have discovered fossils that are more than tens of millions of years old, which provides the latest evidence that these organisms have been around for a long time. Some think that the real meaning of life is more than just a chronological one, and that an organism could be alive today, yet dead tomorrow.
This question is answered by a single word: metabolism. Metabolism is a complex series of chemical reactions in which the various enzymes are coordinated to create specific types of energy. Each single cell of the body carries a set of DNA, which define its shape and size, and the directions it must go in to reproduce. All living things, including plants and animals, use metabolism to create the energy they need to live.
Biology provides many with a great deal of answers to this question. To many people, the definition of life can seem incredibly complicated, even outrageous, because it seems as though the goal is to create something that never existed. After all, there are living things that are vastly different from all of those that aren't alive, and yet they all reproduce. The fact is that the goal of biology is to make the entire planet fit for reproduction so that new life can take hold.
The next time you ask the question "What is Life?" remember that scientists have spent decades studying the workings of the entire living world, attempting to define life from its most basic forms to the most complex of organisms. While there are countless theories as to the exact purpose of living organisms, there is one that stands firm in all aspects: the goal is to maintain homeostasis. Understanding how all of these different types of cells work is the first step toward answering the question.