ribose sugar is used to make nucleic acid however, it is not formed directly in photosynthesis but is formed from glucose. How does glucose form ribose?

Ribose is synthesized from glucose and other monosaccharide molecules in living cells by a process known as pentose phosphate pathway. The pentose phosphate pathway is a series of chemical reactions taking place in the cytosol of cells.

i think that d. wind is the answer.   i missed the question when i answered a. currents.

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.