Geologic processes change Earth’s surface. Some geologic processes are fast and some are slow. Some are constructive and some are destructive. A river makes a valley in rock by erosion. 1) Is the river’s erosion a fast or slow process? Explain your answer.

2) Is the river’s erosion a constructive or destructive process? Explain your answer.

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.