The Order of Events in a Signaling Pathway Can Be

Multiple Choice

The order of events in a signaling pathway can be determined by the analysis of mutants.Cells that express a mutant defective Raf protein cannot be stimulated to proliferate uncontrollably by constitutively active Rasᴰ (dominant active) .This indicates:

A) quiescent cells can be induced to proliferate in the absence of growth factors if they contain a constitutively inactive mutant Raf protein.
B) Raf is upstream of Ras in the signaling pathway.
C) Ras is upstream of Raf in the signaling pathway.
D) Ras mutants are recessive to Raf mutants.