Inside living things, very complex chemical reactions are taking place. Chemical reactions take place outside of living organisms as well, but not on anywhere near the same level. A living organism is a mini-chemistry lab. These chemical reactions are carrying out the functions necessary for life, including breaking down food so that it can be used for energy, creating food, building new cells, repairing body parts and more.
Living Things Grow
What would you like to be when you grow up? Well, first you must eat a lot of food and get your rest. These things are necessary for your body to grow. Like you, other living things also grow. Almost all living things start their lives as smaller infant-like creatures. Over a period of time, they grow and develop into adults. Some lifeforms, such as frogs, start their life in a completely different form, and then change dramatically as they grow. A frog begins its life as a tadpole, then turns into an adult frog. A butterfly starts its life as a caterpillar before maturing into a full grown beautiful butterfly.
Living Things Respond To The Environment Around Them
One of the most important characteristics of living things is that they respond to the environment around them. This one single characteristic makes them very different from non-living things, which do not respond to the environment, but instead just let whatever happens to them happen.
Your own body responds to its environment in order to keep you healthy. You might sneeze to keep dust and germs from entering through your nose, your immune system responds to invaders by producing antibodies, etc. Now consider a non-living thing. If a bear invades a cave, can the cave sneeze to get it out? Does the cave produce antibodies to attack the bear? You can see why this ability is so unique and important to living things.