Stomata are...

Stomata are...

• A. Vascular tissues that transport water.
• B. Outermost protective layer of the leaf.
• C. Large solid stomata structures on stems.
• D. Small openings or pores in a plant leaf that open into the intercellular space.

Answer: (D)

Stomata are small openings or pores on a plant leaf that connect the outside air with the leaf’s interior air spaces (the intercellular spaces). Each pore is flanked by a pair of guard cells that regulate its opening and closing by changing their turgor. When guard cells take in water and swell, the pore opens, allowing carbon dioxide to diffuse into the leaf for photosynthesis and permitting water vapor to exit as transpiration. When water is scarce, the guard cells lose turgor and the pore closes to conserve water. Stomata are part of the epidermis, not vascular tissue and not a solid leaf structure, and they are indeed pores rather than large solid features.

Stomata are small openings or pores on a plant leaf that connect the outside air with the leaf’s interior air spaces (the intercellular spaces). Each pore is flanked by a pair of guard cells that regulate its opening and closing by changing their turgor. When guard cells take in water and swell, the pore opens, allowing carbon dioxide to diffuse into the leaf for photosynthesis and permitting water vapor to exit as transpiration. When water is scarce, the guard cells lose turgor and the pore closes to conserve water. Stomata are part of the epidermis, not vascular tissue and not a solid leaf structure, and they are indeed pores rather than large solid features.