Change genetically (6)
I believe the answer is:
mutate
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">change genetically</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for mutate that I've seen before include "Alter genetically" , "Undergo genetic change" , "Change into a variant form" , "Change into something different" , "(In genetics) change" .)