Living things have five characteristics:

• Organization
  • All living things (organisms) are organized. This means they are specially designed to perform different life functions. The smallest level of organization of living things is cells. Cells are the smallest unit of life.
• Reproduction
  • All organisms have the ability to reproduce. Organisms produce new organisms that are similar to them.
• Adjust to Surroundings
  • All organisms have the ability to adjust (change) to their surroundings. An example of this is that organisms respond to stimuli. For example, if a flea made a dog's nose itch (the stimulus), the dog would scratch its nose (response to stimulus).
• Growth and Development
  • Most organisms grow. When they grow, they go through changes known as development.
• Energy, water and minerals
  • All organisms need these items to function. If they do not get any of these, the organisms die.

If something does not have all of the characteristics listed above, then it is not a living thing!

Do you know how to classify these living things?

Note: There are a few exceptions to the rules above. For example, mules cannot reproduce because they are sterile. This just goes to show that nature doesn't always follow simple rules of organization!