In plants, respiration occurs in

Analyze the question: It asks where respiration takes place in plants. Pay attention to the word "only" in options A, B and D. Those words often signal a wrong answer.

Explain the concept: Respiration is the process by which living cells break down food (glucose) to release energy (ATP):

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy

This happens in the mitochondria of every living cell. It goes on day and night, because all living cells need energy to stay alive, grow, and carry out their activities.

Solution, option by option:

• A. The stomata and lenticel only: Wrong. Stomata and lenticels are openings for gas exchange. Oxygen enters and carbon dioxide leaves through them, but the respiration itself happens inside the cells, not in the openings.
• B. Mesophyll cells only: Wrong. Mesophyll cells are in the leaf and do respire, but so do many other cells, so "only" makes this false.
• C. All living cells: Correct. Cells in the roots, stems, leaves, flowers, fruits and seeds all respire to get energy.
• D. The root only: Wrong. Roots respire, but so does every other living part of the plant.

Answer: C. All living cells

Exam tip: In JAMB Biology, be careful with options that use the word "only". Respiration is a universal life process, so the answer is almost always "all living cells". Remember: photosynthesis happens only in cells with chlorophyll, but respiration happens in every living cell.