Answer:
Sigma factors bind to the promoter region of a particular gene and facilitating the binding of RNA Polymerase to the promoter region (formation of the RNA polymerase holoenzyme complex) in order initiate transcription of the gene.
Put simply - Helps RNA Polymerase do it's job.
Answer:
Proteins.
Explanation:
They are called membrane proteins.
Earths lithospere is solid and sits on top of the softer asthenosphere.
