Final answer:
Oil-palm trees convert carbon dioxide into glucose and other organic compounds during the Calvin cycle of photosynthesis.
Step-by-step explanation:
During photosynthesis, oil-palm trees convert carbon dioxide into glucose and other organic compounds during the Calvin cycle. The Calvin cycle is the light-independent reactions of photosynthesis that convert carbon dioxide from the atmosphere into carbohydrates using the energy and reducing power of ATP and NADPH. This process is essential for plants to produce organic substances from carbon dioxide and is crucial for the survival of living organisms.