Apicomplexan life cycle: 1-zygote, 2-sporozoites, 3-merozoites, 4-gametes.
<a href="//commons.wikimedia.org/wiki/User:Franciscosp2" title="User:Franciscosp2">Franciscosp2</a>
self-made  (using <a rel="nofollow" class="external text" href="http://www.xfig.org">xfig</a> and Linux).