Geneses often prowl in groups, so be careful when traveling underneath them. Unless there is a locked door in the room that impedes your progress, they aren’t worth killing, so just run past. They can be killed by shooting them through the platforms with Wave Beam functionality or by using two Power Bombs. In areas of Sector 1, the X parasites from the defeated Geneses will often transform into yellow-colored Zebesians, so stay alert.