There's a book called 'Quantum Evolution' by Johnjoe McFadden that tries to answer the question of what processes in biology exploit quantum effects.

An obvious one is photon capture in photosynthesis that seems to rely on quantum effects to transfer energy around the antenna complex. I'm no doubt mangling that explanation, so see :

https://en.m.wikipedia.org/wiki/Quantum_biology#Photosynthes...