In a series of experiments, genes that code for mutant forms of a receptor tyrosine kinase are introduced into cells. The cells also express their own normal form of the receptor from their normal gene, although the mutant genes are constructed so that they are expressed at considerably higher concentrations than the normal gene. What would be the consequences of introducing a mutant genes that codes for a receptor tyrosine kinase which:

a. lacks its extracellular domain
b. lacks its intracellular domain