The HACNS1 region from all species studied produced expression in the eye, ear, and pharyngeal arches, whereas only the human HACNS1 region produced significant expression in the limb bud. Explain how gene expression can be differentially regulated in different tissues.

The scales shown in the introduction measure mass, or the amount of matter in a particular object. the scientific law of conservation of mass states that matter cannot be created or destroyed during a chemical reaction, but it can change from one form to another. did the simulation support this scientific law? explain why or why not.