If photosynthesizing green algae are provided with CO2 containing an isotope of oxygen called "heavy oxygen" (18O), later analysis will show that all of the following molecules produced by the algae contain 18O except

A. O2.
B. glucose.
C. Glyceraldehyde 3-phosphate (G3P).
D. ribulose bisphosphate (RuBP).

A) O2

Explanation:

The CO2 is used for the synthesis of high energy molecules in photosynthesis. The carbon molecules are joined in the dark  reaction of photosynthesis on the expenditure of energy produced in light reaction (ATP and NADPH).

A. O2.

Explanation:

Carbon dioxide is known to have radioactive oxygen. We have to find where this radioactive oxygen is incorporated. This carbon dioxide couples to the RuBisCO enzyme and transforms ribulose bisphosphate into two 3-phosphoglyceric acid molecules. This is then transformed into glucose and ribulose bisphosphate is regenerated by 3-phosphoglyceric acid. Radioactive oxygen binds to 3-phosphoglyceric acid, glucose, and ribulose bisphosphate.

lysosome is this part of the cell is surrounded by a very thick outer membrane to protect the rest of the cell from its strong enzymes.