Characteristics of Animals
Picture of Mother kangaroo and Joey : Did you know that A baby kangaroo rides around in its mother's pouch. To enter, it puts its forepaws on the pouch, dives in, and turns a somersault. Out pops its head!
Scientists have identified and named more than 1 million species of animals! They include everything from ants to zebras! Some estimate that there are 3 to 30 million more to identify and name.
Animals have five characteristics:
- Animals cannot make their own food. Some eat plants, some eat animals, and some eat both.
- Animals digest their food.
- Many animals move from place to place to find food, mates, a better place to live or to escape enemies. If they can't move or they move slowly, they will have adaptations that let them take care of these needs.
- Animals have many cells.
- Animal cells are eukaryotic. They each have a nucleus and organelles surrounded by membranes.
- Cells that do not have a nucleus and other organelles with membranes around them are prokaryotic cells. Bacteria are examples of prokaryotic cells.
- A eukaryotic cell has a nucleus and other organelles with membranes around them. Animal, plant, fungi and protista cells are eukaryotic.
- Body symmetry - the way body parts are arranged around a point or central axis.
Directions on the body - used to describe areas on the body of an animal.
Pattern of body development - a sequence of developmental steps.
Formation of germ layers - layers of specialized cells in the early development.
Characterisitics of Vertebrates and Invertebrates