What does it mean to be living? All living things share eight characteristics that classify them as being alive.

Click on the pictures below to learn more about the characteristics of life.

If all living things share these same eight characteristics, what makes living things different from each other? What makes an animal different from a bacterium or a plant?

All living things are grouped into one of six kingdoms. Each of these kingdoms has distinct characteristics. Classification starts with the following criteria:

1. Number of cells (unicellular or multicellular)
2. Type of cells (prokaryotic or eukaryotic)
3. Method of nutrition (autotroph or heterotroph)
4. Mode of reproduction (asexual reproduction or sexual reproduction)

In this lesson, you will focus on the differences between plant and animal cells.