They are complete organisms (most are unicellular) that contain all the facilities for performing the same body functions that we humans can perform.
(They; are; complete organisms (most are unicellular) that contain all the facilities for performing the same body functions) (most; are; unicellular) (complete organisms (most are unicellular; contain; all the facilities for performing the same body functions) (the same body functions; can perform; we humans)
They most complete organisms (most are unicellular the same body functions
are are contain can perform
complete organisms (most are unicellular) that contain all the facilities for performing the same body functions
unicellular
all the facilities for performing the same body functions
we humans