Final answer:
The primary function of mesophyll in a leaf is to capture sunlight. This is achieved through the regulation of transpiration, primarily through the opening and closing of stomata on the leaf surface. Stomata must open to allow air containing carbon dioxide and oxygen to diffuse into the leaf for photosynthesis and respiration.
Step-by-step explanation:
Leaves are covered by a waxy cuticle on the outer surface that prevents the loss of water. Regulation of transpiration, therefore, is achieved primarily through the opening and closing of stomata on the leaf surface. Stomata are surrounded by two specialized cells called guard cells, which open and close in response to environmental cues such as light intensity and quality, leaf water status, and carbon dioxide concentrations. Stomata must open to allow air containing carbon dioxide and oxygen to diffuse into the leaf for photosynthesis and respiration. When stomata are open, however, water vapor is lost to the external environment, increasing the rate of transpiration. Therefore, plants must maintain a balance between efficient photosynthesis and water loss.
The primary function of mesophyll in a leaf is capturing sunlight through photosynthesis. Mesophyll cells contain chloroplasts, which are the organelles responsible for photosynthesis. Photosynthesis is the process by which plants, algae, and some bacteria convert sunlight into chemical energy to produce glucose and oxygen. Mesophyll cells are located in the middle layer (mesophyll tissue) of a leaf and are specialized for the absorption of light energy and the exchange of gases (carbon dioxide and oxygen) necessary for photosynthesis.