Final answer:
The process where plant cells use oxygen to extract energy from food is known as cellular respiration, an aerobic process that results in the production of ATP and takes place in the mitochondria.
Step-by-step explanation:
The name of the process in which plant cells use oxygen to get energy from food is cellular respiration. Although plants are well-known for photosynthesis, they also undertake cellular respiration to access the energy stored in the glucose molecules they have synthesized. During cellular respiration, glucose (C6H12O6) and oxygen (O2) react to form carbon dioxide (CO2), water (H2O), and release energy in the form of ATP, this is an aerobic process that occurs in the mitochondria of plant cells.