Prophase is the first step in mitosis and many changes occur. Chromatin fibers become coiled into chromosomes, with each chromosome having 2 chromatids joined at a centromere. The mitosis spindle, composed of microtubules and proteins, form in the cytoplasm.
<span>The crust and the upper layer of the mantle together make up a zone of rigid, brittle rock called the lithosphere. </span>
the answer is differentiation