Cephalization is the differentiation of end part of the body into a head in which nerve tissue is concentrated. Sponges have a very loose nervous system and their cells work individually, not controlled by a nervous system. Since they have no defined head as a consequence of concentrated nervous system, the sponges could not have cephalization either.
From the TOP TO BOTTOM it is tertiary 1
secondary 10
primary 90
Producers 100
Explanation:
Radioactive elements comprise a majority of the "ACTINIDES"
These are elements in the bottom row of the periodic table.
Sixty-five percent of the mass of bone<span> is an </span>organic<span> compound called hydroxyapatite. All </span>bones<span> formed by intramembranous ossification are irregular</span>bones<span>.
TRUE</span>
