Let’s Begin Classifying

 Characteristics that ALL animals have: 1. made of many cells 2. reproduce in some way 3. move in some way 4. grow, develop, and change 5. must eat food instead of producing their own (main difference between plants and animals)

 Classify- to place things into groups based on their characteristics  As of 2010, scientists have discovered over 1,367,000 species, or types, of animals.  Many animals share characteristics.  Each animal has its own unique characteristics.  How do scientists classify these animals?

 Vertebrate- an organism with a backbone  Invertebrate- an organism without a backbone

This sea star has radial symmetry. Think “few.” This sea urchin has spherical symmetry. It’s shaped like a ball and has “many” lines of symmetry. These animals have bilateral symmetry. Think “one.” This sponge has “no” lines of symmetry.