Chordates and their Characteristics
The basic characteristics of chordates are:
Notochord:
It is rod like structure made up on semi-rigid body of cells. It is enclosed in the sheath of connective tissues. It is located dorsal to the alimentary canal and ventral to nervous system running for anterior to posterior end. Its major is to provide support and stiffens the body. It acts like skeletal axis. In most animals backbone is present instead of notochord.
Pharyngeal Pouches:
It is present in some stages of chordates. Pharyngeal pouches develop into gill slits in the adult animals that live in water and breath by gills. While in land animals they replaced by other organs e.g. inner part of ear.
Hollow Dorsal Nervous System:
In all chordates a hollow dorsal nervous system is present, whose anterior part enlarge into brain. Postanal tail is also present at some stages beyond anus.
So, of course, audiobooks will not replace paper or electronic books. But they can complement them perfectly. This is especially valuable for children and adults with a leading auditory channel of perception. Only a neuropsychologist will help to find out the leading channel with the help of testing. And, by the way, this is useful knowledge: you can take this into account and help your child to better absorb information.