the phospholipids are tightly packed togther and the membrane has a hydrophobic interior.
Answer:
Chordates share some common traits. At some point in their life cycle, they have a notochord, a nerve cord, and pharyngeal (fayr uhn JEE uhl) slits in the neck or throat. The notochord is a flexible rod that supports the animal's back. ... Sharks are one type of vertebrate animal that have backbones made of cartilage.
