Which of the following provides 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 signal each other in a process called 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.

Question

Quizplus · Accepted Answer

The similarity of signal transduction molecules in distantly related organisms suggests that these pathways are ancient and have been conserved throughout evolution, indicating their early origin in the history of life.

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