Genetic Expression: Same Genes Can Produce Different Results by Brian Thomas, M.S.* Genes could be thought of as brick molds, used to construct materials for building the physical structures of living organisms. They carry the codes to help make proteins, which then make up different cells that are combined together to form mega-structures called tissues. New research has shed more light on how genes are used by cells to build the different tissues needed by complex living creatures. Genes—which make up a very small fraction of DNA—were thought to be the central genetic features that drive cell function and embryonic...