Vehicle ownership by expats in Saudi. Public transport is almost negligible in Saudi Arabia. As an expatriate, it is really convenient if you have a car of your own. For those of you with your families, it is almost impossible to survive without a vehicle.
Phyla with a true coelom and digestive system are divided into two groups, the protostomes and the deuterostomes. As the hollow sphere of cells known as a blastula develops, an invagination produces an opening called the blastopore. In protostomes, the blastopore becomes the mouth.
In this lesson we explored the organisms that make up phylum Chordata and discussed their body symmetry. All chordates share four common characteristics: a nerve cord, a notochord, pharyngeal slits, and a postanal tail. Chordates, including humans, are also all classified as having bilateral symmetry and can be divided into a left and right side.