Why is oxygen important for roots?

• A. Oxygen helps roots to photosynthesize
• B. Roots need oxygen for energy and nutrient uptake
• C. Oxygen storage in root cells is the main function
• D. Oxygen is irrelevant to root function

Answer: (B)

Oxygen is essential for roots because it fuels cellular respiration, the process that releases energy from sugars. In root cells, mitochondria use oxygen to produce ATP, and this energy powers active transport mechanisms that move nutrients from the soil into the plant. Without enough oxygen, these energy-dependent pumps and transporters can’t work well, so nutrient uptake slows and root growth can be hindered. This is especially important in soils with poor aeration or waterlogging, where oxygen supply is limited and respiration drops. Roots don’t photosynthesize, and oxygen isn’t stored as a major function in root cells; the primary role of oxygen here is to provide the energy needed for nutrient uptake and maintaining root health. Oxygen isn’t irrelevant to root function—without it, roots can’t efficiently acquire the nutrients they need.