Signal transduction is part of a cell's response to an external signal. although signal transduction pathways can differ in their details, there are some common elements. select the six statements that accurately describe signal transduction pathways.1. a receptor changes conformation upon binding, transmitting a signal across the cell membrane.2. signal transduction cascades, often involving protein kinases, amplify a signal intracellularly.3. signal transduction cascades directly transmit a single stimulus to a single target.4. a second messenger may carry a signal from the cell membrane to an organelle.5. a ligand, such as a hormone, binds to a specific cell surface receptor on a target cell.6. a ligand phosphorylates protein residues, ending the signaling cascade inside the cell.7. a receptor may pass on a signal by interacting with another protein or by acting as an enzyme.8. phosphatases remove phosphoryl groups from polypeptides, regulating a cell's response.9. a second messenger carries a signal from a tissue or organ to a target cell.