gas exchange in plants

Leaf

Lower side of the leaf you can find the stomata (site of gas exchange)

Carbon dioxide diffuses in and goes to the spongy mesophyll- lots of space for gases to diffuse in and to help maintain concentration gradient

Palisade mesophyll- where most photosynthesis occurs because it is closer to the top to receive direct sunlight

Gas exchange at a stomata

Oxygen diffuses out of the stomata

carbon dioxide diffuses in through the stomata

To reduce water loss by evaporation, stomata close at night when photosynthesis wouldnt be occurring

Stomata opening- guard cells swollen

Stomata closing- guard cells shrinking

Xerophytic plants

Are adapted to survive in environments with limited water

Xerophytic plants

They have structural features to enable efficient gas exchange to occur whilst also limiting the water loss

Curled leaves to trap moisture to increase local hummidity

Hairs to trap moisture to increase local hummisity

Sunken stomata to trap moisture to increase local hummidity

Thicker cuticle to reduce evaporation

Longer root network to reach more water