Cell cycle.
<P>
   The mitotic (M) phase alternates with interphase, which is composed of
   2 growth phases (G[1] and G[2]) and a S (DNA synthesis) phase.
<P>
   In the M phase, mitosis divides the nucleus.
<P>
   Then  cytokinesis  divides  the  cytoplasm,  producing  2  genetically
   identical "daughter" cells.
<P>
   Exercise:  <A ClAsS=ACT Href="http://media.pearsoncmg.com/bc/bc_campbell_biology_7/media/activities/load.html?12&amp;B" oNClick="popact('http://media.pearsoncmg.com/bc/bc_campbell_biology_7/media/activities/load.html?12&amp;B');txtcolor('cycle1','gray');return false;" Id=cycle1><iMg sRc="/images/tutorial.gif" aLt='' boRDer=0></A>