Question

Which organisms would die first in the absence of sunlight?

Answer 1

by organisms i hope you mean living because the first to die off would be plants this is because they get their food from photosynthesis which occurs with sunlight. and then eventually everything else would die because the plants make oxygen for us to stay alive.
~hope i helped

Answer 2

Organisms that utilize photons and nutrients from the abiotic environment.

Hope this helps, have a nice day! :-)