Final answer:
Glucose is the molecule that does not take part in the light-independent reactions of photosynthesis; rather, it is a product of the photosynthetic process which includes the Calvin cycle.
Step-by-step explanation:
The exception among the molecules listed that does not take part in the light-independent reactions, also known as the Calvin cycle, is glucose. The molecules that are involved in the Calvin cycle include Ribulose bisphosphate (RuBP), 3-Phosphoglycerate (PGA), and ribulose monophosphate. RuBP is a critical molecule that combines with CO₂ in the first stage of the Calvin cycle, which is catalyzed by the enzyme RuBisCO, to form PGA. Through a series of reactions involving ATP and NADPH from the light-dependent reactions, these molecules eventually lead to the production of G3P, some of which can be used to form glucose. However, glucose itself is not a direct participant in the light-independent reactions but rather a product of the entire photosynthetic process.