Cells grown in the laboratory are mixed with a dye molecule that is unable to pass through the plasma membrane. if a ligand is added to the cells, observations show that the dye enters the cells. what type of receptor did the ligand bind to on the cell surface?

The ligand bind with an ion channel receptor present on the surface of the cell. After combining the ion channel receptor opened a pore in the membrane that permitted the ionic dye to move within the cell. These ion channel receptors are generally the multimeric proteins situated in the plasma membrane and possess the tendency to close and open in response to mechanical or chemical signals.

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."