Which of the Following Describes Cell Communication Systems

Multiple Choice

Which of the following describes cell communication systems?

A)
Cell signaling evolved more recently than systems such as the immune system of vertebrates.
B) Communicating cells are usually close together.
C) Most signal receptors are bound to the outer membrane of the nuclear envelope.
D) Lipid phosphorylation is a major mechanism of signal transduction.
E) In response to a signal, the cell may alter activities by changes in cytosol activity or in transcription of RNA.