The remaining animals, the great majority—comprising some 29 phyla and in excess of one million species—form the Bilateria clade, which have a bilaterally symmetric system program. The Bilateria are triploblastic, with 3 very well-formulated germ levels, and their tissues variety distinct organs. The digestive chamber has two openings, a mouth https://nybookmark.com/story22102954/the-2-minute-rule-for-cheap-pet-food