BIOLOGY Chapter Notes -Fruit Anatomy, Transpiration, Osmosis
Document Summary
Gaseous exchange in plants is achieved by stomata and lenticels. The epidermis has tiny pores called stomata (singular, stoma) that control transpiration and gas exchange with the air. During the day when photosynthesis occurs, the oxygen released from the process is utilized for respiration. The figure below describes the structure of stomata in the leaf epidermis. Stomata control the transpiration of water vapor and the exchange of carbon dioxide and oxygen. Stomata are flanked by guard cells that swell or shrink by taking in or losing water through osmosis. When they do, they open or close the stomata. Thick woody stems, and even pericarp (fruit covers) in plants, also have openings called lenticels on their outer surfaces for gaseous exchange. The interior of the woody stems in plants is mostly made up of dead tissue which provides mechanical support and the cells here do not respire. The figure below is one example of lenticels.
