Vertebrates are complex animals, but they still share some characteristics with invertebrates. Mia volunteers at her city’s aquarium for the summer. She enjoys observing the jellyfish and the clownfish. After discussing the animals with the aquatic caretaker, she thinks about how their different parts work together. What kind of organization describes an animal’s body structure? A. notochord, chord, throat pouches B. cells, tissues, organs, organ systems C. wings, fins, muscular foot, tube feet, jet propulsion D. fish, amphibians, reptiles, birds, mammals