What are tiny openings in plant tissue that regulate water vapor loss and gas exchange?

What are tiny openings in plant tissue that regulate water vapor loss and gas exchange?

• A. Stoma
• B. Chlorophyll
• C. Thylakoid sac
• D. Carotenoids

Answer: (A)

Stomata are tiny openings on the leaf surface that regulate water vapor loss and gas exchange. Each opening is formed by two guard cells; when these cells become turgid, the stomata open to let carbon dioxide in for photosynthesis and oxygen and water vapor out. They respond to light, humidity, CO2 levels, and hormonal signals like ABA, opening in favorable conditions and closing to conserve water during drought. The other options are internal components: chlorophyll is the pigment that captures light, thylakoid sacs are membranes inside chloroplasts where the light reactions occur, and carotenoids are pigments that assist in light capture and protect against damage.

Stomata are tiny openings on the leaf surface that regulate water vapor loss and gas exchange. Each opening is formed by two guard cells; when these cells become turgid, the stomata open to let carbon dioxide in for photosynthesis and oxygen and water vapor out. They respond to light, humidity, CO2 levels, and hormonal signals like ABA, opening in favorable conditions and closing to conserve water during drought. The other options are internal components: chlorophyll is the pigment that captures light, thylakoid sacs are membranes inside chloroplasts where the light reactions occur, and carotenoids are pigments that assist in light capture and protect against damage.