JAMB - Biology (2009 - No. 38)
Use the diagram above to answer this question.
The structure that controls loss of water vapour during transpiration is labelled
l
ll
lll
lV
Explanation
Stomata regulate gas exchange between the plant and environment and control of water loss by changing the size of the stomatal pore.
Guard cells are cells surrounding each stoma. They help to regulate the rate of transpiration by opening and closing the stomata.