Which of the Following Statements Best Describes an Aspect of Signal

Multiple Choice

Which of the following statements best describes an aspect of signal transduction?

A) When signal molecules first bind to receptor tyrosine kinases, the receptors phosphorylate a number of nearby molecules.
B) In response to some G protein-mediated signals, a special type of lipid molecule associated with the plasma membrane is cleaved to form IP3 and calcium.
C) In most cases, signal molecules interact with the cell at the plasma membrane, enter the cell, and eventually enter the nucleus.
D) Protein kinase A activation is one possible result of signal molecules binding to G protein-coupled receptors.