Lipid-soluble signal molecules, such as testosterone, cross the membranes of all cells but affect only target cells because
A)only target cells retain the appropriate DNA segments.
B)intracellular receptors are present only in target cells.
C)most cells lack the Y chromosome required.
D)only target cells possess the cytosolic enzymes that transduce the testosterone.
E)only in target cells is testosterone able to initiate the phosphorylation cascade leading to activated transcription factor.

Question

Quizplus · Accepted Answer

Lipid-soluble signal molecules, such as testosterone, can cross the membrane of all cells. However, intracellular receptors for these signal molecules are present only in target cells. Thus, only target cells can respond to the signals of lipid-soluble signal molecules.

Lipid-Soluble Signal Molecules, Such as Testosterone, Cross the Membranes of All