The answer is photosynthesis
I beleive that the plasma membrane is B. Semi permeable
A. atom
atoms are described to be the basic unit of a chemical element.
30.6 • 150 is the same as 4,500 + 90, or 4,590 million kilometers, oddly enough, this isn't one of the options for an answer. Perhaps there was a typo?
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.