What regulates gas exchange in leaves and opens in light?

What regulates gas exchange in leaves and opens in light?

• A. Stomata
• B. Lenticels
• C. Phloem
• D. Xylem

Answer: (A)

Stomata are the openings on a leaf’s surface that regulate gas exchange. They’re surrounded by guard cells that control the pore’s size. In light, guard cells become turgid as ions (like potassium) are pumped in, drawing water in and swelling the cells. This opens the pore, allowing carbon dioxide to enter for photosynthesis and letting oxygen and water vapor exit. In darkness, guard cells lose turgor and the stomata close to reduce water loss. Lenticels are openings on stems, not leaves, and phloem and xylem are the tissue systems for transport, not for regulating leaf gas exchange in response to light.

Stomata are the openings on a leaf’s surface that regulate gas exchange. They’re surrounded by guard cells that control the pore’s size. In light, guard cells become turgid as ions (like potassium) are pumped in, drawing water in and swelling the cells. This opens the pore, allowing carbon dioxide to enter for photosynthesis and letting oxygen and water vapor exit. In darkness, guard cells lose turgor and the stomata close to reduce water loss.

Lenticels are openings on stems, not leaves, and phloem and xylem are the tissue systems for transport, not for regulating leaf gas exchange in response to light.