The oxygen atoms in the h2o broken down during photosynthesis end up in:

The correct answer is "oxygen is released as byproduct".

Explanation:

Photolysis of water in photosystem II leads to the production of three things:

1. High energy electron

2. Hydrogen ions

3. Oxygen

1. High energy electrons are passed through ETC and help in production of H+ ion concentration gradient. This gradient is used to produce ATP

2. Hydrogen ions directly help in creating the concentration gradient

3. Oxygen is released out of the cell as the byproduct. This oxygen is used in cellular respiration by different organisms.

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.