My classmate's statement in incorrect because plants are also composed of cells.
All living things are composed of cells. A cell is the smallest unit of living organisms. Cells obtain energy via the process of cellular respiration. During cellular respiration, glucose is broken down to yield carbon dioxide and water.
In photosynthesis, carbon dioxide and water are combined to form glucose. The two processes are opposites of each other. Plants produce their own food via photosynthesis. Since plants are composed of cells, plant cells also undergo cellular respiration therefore my classmate's statement in incorrect.
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