Where do cells get the chemicals needed to synthesize other molecules?

Some Chemicals simply pass through the cell membrane. Other chemical pass through membranes attached to the cell membrane which allows specific types of Chemical through and block others. The chemicals are either blocked or allowed through based on the shape of the molecule.

small, big, or no change could occur in the phenotype. it could cause something as simple as a cats ears to curl backwards or something as frighting as death. it could also occur in the protien-coding area and have an effect on that but no effect on the amino acids. what has to occur is a changing in the hox gene or the control gene.