I didn't think so, there is one important reason in the battle Mercer bleeds and lose his arms and se can see a piece of bone.

Alex dont have any organ so there is no blood or bone, whe are able to see it at the end of the first Game and trohw the game for his resistant to the thermobaric explosion, things that make a lot of damage to Heller because his body is still human, he still having organs. So after consume Green Mercer is able to control biomass so he can pick a infected a create a clon of his own, but whitout the physical charasteristic of Zeus