They do. Ever heard of night-blooming flowers? And I have heard you should plant potatoes at night, during certain phases of the moon.
shhhhhhhh cuz they're sleeping
from memory they dont photosynthesise at night and produce carbon dioxide instead of oxygen. this may explain why people feel more tired at night too as the CO2 levels are higher
lol im nocturnal so that goes in favour of your argument. tis an old memory and possibly incorrect.
Because there are not enough ultraviolet rays for them to collect.