What process adds oxygen to the atmosphere

Astudent is looking through a microscope at some cells of an onion root tip. many of these cells are undergoing division since the root tip grows quickly and requires more cells. which cell most recently underwent metaphase? w x y z

If the rna molecule in a human has the nucleotide sequence of guu, this would the amino acid valine would be needed to make the protein. how would this cha process was occurring in a mushroom?

Where is most of the fresh water on earth found a in the ocean b in glaciers and in ice caps c in rivers d in the soil