Answer:
The animal kingdom is divided into vertebrates and invertebrates
Step-by-step explanation:
Invertebrate animals are those that have no internal skeleton, bone or cartilaginous. They are generally small animals. Examples: arachnids, insects, earthworms.
While vertebrate animals have a bone skeleton or cartilaginous bones. The skeleton is formed by the spine to which the different bones of the skeleton articulate. Examples: birds, fish, reptiles.
The main characteristic that all animals share is that they are multicellular organisms, which are organized and each one has its specific function. These cells have a nucleus and have no cell wall.