What are some unanswered questions about photosynthesis

Here's one I found interesting.

Can we ever beat photosynthesis?

-It’s one of the holy grails of energy; coming up with a material for capturing the energy of the sun which can beat the efficiency of photosynthesis. This is an incredibly challenging problem, to say the least. And it’s one that could have an outsize impact on our very way of life, leading to energy from water splitting and biomass from energy conversion.

can photosynthesis ever work at night from the light of the moon?

can plants photosynthesize the whole day?

does photosynthesis need carbon dioxide?

theres a few :D

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.