Natural selection directly affects which of the following?

Why does controlling transcription affect prokaryotic gene expression?

According to the rna world hypothesis, rna acted as the genetic material and catalyzed reactions in ancient cells. what conclusion can you draw from this?               a.  this implies that dna and proteins aren't essential in cells today.    b.  this implies that rna can catalyze any chemical reaction that enzymes catalyze.    c.  this implies that if a cell has a problem with its dna, its rna can compensate for the damaged dna.    d.  this implies that dna and proteins evolved after rna.

What is a food chain? a.different animals located in different communities b. energy transferred from the sun to plants and then to a series of living things c. rows of crops, such as lettuce, in a field d.animals using one another as food for energy and growth