Do plants undergo photosynthesis or cellular respiration or both?
Plants undergo both: photosynthesis and cellular respiration. Photosynthesis is the process by which plants consume carbon dioxide and water and produce food, in the form of glucose molecule. Plants carry out this process only in the presence of sunlight. The chemical reaction for this process is given as:
6 CO2 + 6 H2O + sunlight -> C6H12O6 + 6O2
This process also produces oxygen, which is essential for survival of aerobic life forms, such as human beings.
Cellular respiration is the process by which plants and other life forms produce energy. The chemical reaction for cellular respiration is given as:
C6H12O6 + 6O2 -> 6CO2 + 6 H2O + energy
This process is complementary to photosynthesis. A key feature of cellular respiration is generation of energy in the form of ATP molecules. Energy is required for all the life processes and is a requirement for life sustenance.
Plants carry our both the processes, thus generating food and energy. In fact, cellular respiration is carried out continuously throughout their life, while photosynthesis is only carried out during the hours when sunlight is available.
Hope this helps.
check Approved by eNotes Editorial