Question 11
Photosynthesis and Plant NutritionThe flow of air and water in or out of the mesophyll layer of a leaf is controlled by the
- A.stomata
- B.lenticels
- C.air spaces
- D.guard cells.
Show the answer and explanation
Answer: D (guard cells.)
Explanation
Gases and water vapour pass through the stomata, but it is the guard cells that change shape to open or close each pore, so they control the flow.