cell (biology) the basic structural and functional unit of all organisms; they may exist as independent units of life (as in monads) or may form colonies or tissues as in higher plants and animals
being,
organism the state or fact of existing; "a point of view gradually coming into being"; "laws in existence for centuries"
zygote The diploid cell formed by the fusion of two haploid gametes during fertilization in eukaryotic organisms with sexual reproduction.\n(source: FAO)