Water with dissolved soil in it percolating through a rock is an explane of what? ( weathering, erosion, or deposition)

I'm pretty sure it's deposition because the sediments in the water(soil) are building up on the rock.

the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.