Gametes (3)
I believe the answer is:
ova
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">gametes</span>' is the definition.<br/ ><span class="explanation-format__explanation">(ovum is a kind of gamete)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for ova that I've seen before include "Latin egg-cells" , "Female reproductive cells" , "Prerequisite for procreation" , "Potential life sources" , "Likely end for Russian Fed cup players" .)