Cnidarians were the first phylum that scientists saw tissue level organization in. Tissue level organization meaning cells all of one type start to function in a unified way.
It can also be called a column.
<u><em>Turtles are reptiles of the order Characterized by a special bony or cartilaginous shell developed from their ribs and acting as a shield.A turtle is faaster than a human,But it shell is heavy,and its house.</em></u>
They provide a critical habitat for many other organisms <span>best explains the role of deep sea coral reefs in the environment.</span>
