Which of the Following Poses the Best Evidence That Cell-Signaling

Multiple Choice

Which of the following poses the best evidence that cell-signaling pathways evolved early in the history of life?

A) Cell-signaling pathways are seen in "primitive" cells such as bacteria and yeast.
B) Bacteria and yeast cells may undertake quorum sensing.
C) Signal transduction molecules identified in distantly related organisms are similar.
D) Most signals in all types of cells are received by cell surface receptors.
E) Signals in bacteria are hydrophobic and do not require a cell surface receptor.