1. Which type of signaling DOES NOT involve a soluble signal molecule? a) endocrine b) paracrine c) neuronal d) contact dependent 2. Which statement concerning signal transduction is true? a) Cells can only respond to one signal at a time. b) Each cell has exactly one type of receptor, present in multiple copies. c) Signal transduction usually occurs in a single step. d) The biological response to a given ligand may not be the same in each cell. e) None of these answers are true. 3. Receptors involved in signaling can be found a) in the plasma membrane b) in the nucleus c) in the cytosol or the plasma membrane d) in the cytosol, nucleus or plasma membrane.